If I can ride a bicycle at the rate of 5 meters per second, how long will it take to ride a distance of 12km at the same rate?

Mathematics
If I can ride a bicycle at the rate of 5 meters per second, how long will it take to ride a distance of 12km at the same rate?

ScanSolve AI Answer


Step 1: Expand (3x2)2(3x-2)^2.
(3x2)2=9x212x+4(3x-2)^2 = 9x^2 - 12x + 4

Step 2: Subtract (3x2)(3x-2).
9x212x+4(3x2)=9x212x+43x+29x^2 - 12x + 4 - (3x - 2) = 9x^2 - 12x + 4 - 3x + 2

Step 3: Combine like terms.
9x215x+69x^2 - 15x + 6

Step 4: Factor the expression.
9x215x+6=3(3x25x+2)=3(3x2)(x1)9x^2 - 15x + 6 = 3(3x^2 - 5x + 2) = 3(3x - 2)(x - 1)
3(3x-2)(x-1)


Step 1: Common denominator is 12.
y24=3y212,y6=2y12\frac{y^2}{4} = \frac{3y^2}{12}, \quad \frac{y}{6} = \frac{2y}{12}

Step 2: Subtract the fractions.
3y2122y12=3y22y12\frac{3y^2}{12} - \frac{2y}{12} = \frac{3y^2 - 2y}{12}
\dfrac{3y^{2-2y}{12}}


Step 1: Expand the numerator.
(4x+3)2=(4x+3)(4x+3)=16x2+24x+9(4x + 3)^2 = (4x + 3)(4x + 3) = 16x^2 + 24x + 9

Step 2: Divide by 7.
16x2+24x+97\frac{16x^2 + 24x + 9}{7}
\dfrac{16x^{2+24x+9}{7}}


Step 1: Expand the numerator.
(5x+4)2=(5x+4)(5x+4)=25x2+40x+16(5x + 4)^2 = (5x + 4)(5x + 4) = 25x^2 + 40x + 16

Step 2: Divide by 37.
25x2+40x+1637\frac{25x^2 + 40x + 16}{37}
\dfrac{25x^{2+40x+16}{37}}


Step 1: Write factorials.
7!=7×6×5!,2!=2×1=27! = 7 \times 6 \times 5!, \quad 2! = 2 \times 1 = 2

Step 2: Simplify.
7!5!2!=7×6×5!5!2=7×62=21\frac{7!}{5! \cdot 2!} = \frac{7 \times 6 \times 5!}{5! \cdot 2} = \frac{7 \times 6}{2} = 21
21


Step 1: Write numerator up to 5!.
9!=9×8×7×6×5!9! = 9 \times 8 \times 7 \times 6 \times 5!
Denominator: 5!2!2!=5!22=5!45! \cdot 2! \cdot 2! = 5! \cdot 2 \cdot 2 = 5! \cdot 4

Step 2: Simplify.
9×8×7×6×5!5!4=9×8×7×64\frac{9 \times 8 \times 7 \times 6 \times 5!}{5! \cdot 4} = \frac{9 \times 8 \times 7 \times 6}{4}

Step 3: Compute step-by-step.
9×8=729 \times 8 = 72
72×7=50472 \times 7 = 504
504×6=3024504 \times 6 = 3024
3024÷4=7563024 \div 4 = 756
756


Step 1: Pascal's triangle row for (a+b)5(a + b)^5 (coefficients: 1, 5, 10, 10, 5, 1).
(a+b)5=1a5b0+5a4b1+10a3b2+10a2b3+5a1b4+1a0b5(a + b)^5 = 1 \cdot a^5 b^0 + 5 a^4 b^1 + 10 a^3 b^2 + 10 a^2 b^3 + 5 a^1 b^4 + 1 \cdot a^0 b^5

Step 2: Write the expansion.
a5+5a4b+10a3b2+10a2b3+5ab4+b5a^5 + 5a^4 b + 10 a^3 b^2 + 10 a^2 b^3 + 5 a b^4 + b^5
a^{5 + 5a^{4}b + 10a^{3}b^{2} + 10a^{2}b^{3} + 5ab^{4} + b^{5}}


Step 1: Use binomial theorem or Pascal's triangle (same coefficients as ).
(x+2)5=x5+5x4(2)+10x3(2)2+10x2(2)3+5x(2)4+(2)5(x + 2)^5 = x^5 + 5 x^4 (2) + 10 x^3 (2)^2 + 10 x^2 (2)^3 + 5 x (2)^4 + (2)^5

Step 2: Compute powers of 2.
21=2,22=4,23=8,24=16,25=322^1 = 2, \quad 2^2 = 4, \quad 2^3 = 8, \quad 2^4 = 16, \quad 2^5 = 32

Step 3: Multiply coefficients.
5×2=105 \times 2 = 10
10×4=4010 \times 4 = 40
10×8=8010 \times 8 = 80
5×16=805 \times 16 = 80

Step 4: Full expansion.
x5+10x4+40x3+80x2+80x+32x^5 + 10x^4 + 40x^3 + 80x^2 + 80x + 32
x^{5 + 10x^{4} + 40x^{3} + 80x^{2} + 80x + 32}


Step 1: Convert m/s to km/h (multiply by 36001000=3.6\frac{3600}{1000} = 3.6).
340×3.6340 \times 3.6

Step 2: Compute.
340×3=1020340 \times 3 = 1020
340×0.6=204340 \times 0.6 = 204
1020+204=12241020 + 204 = 1224
Speed = 1224 km/h
1224 km/h


Step 1: Convert distance to metres.
18.8km=18.8×1000=18800m18.8 \, km = 18.8 \times 1000 = 18800 \, \mathrm{m}

Step 2: Convert time to seconds.
1h10min=(60+10)×60=70×60=4200s1 \, h \, 10 \, min = (60 + 10) \times 60 = 70 \times 60 = 4200 \, \mathrm{s}

Step 3: Calculate speed.
18800m4200s=18842=94214.476\frac{18800 \, m}{4200 \, s} = \frac{188}{42} = \frac{94}{21} \approx 4.476

Step 4: To 3 significant figures.
4.48 m/s
4.48 m/s

Was this helpful?

Still stuck on this one?

Ask a follow-up, and the answer starts from this question.

Got a different question?Ask your own question