Here are the solutions to the problems:
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Evaluate 3x2+4x−5 given that x=1.
Step 1: Substitute x=1 into the expression.
3(1)2+4(1)−5
Step 2: Perform the calculations.
3(1)+4−5
3+4−5
7−5=2
The value of the expression is 2.
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Evaluate x1+2x+1x given that x=2.
Step 1: Substitute x=2 into the expression.
21+2(2)+12
Step 2: Simplify the second fraction.
21+4+12
21+52
Step 3: Find a common denominator and add the fractions.
The common denominator for 2 and 5 is 10.
2×51×5+5×22×2
105+104
105+4=109
The value of the expression is 109.
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Evaluate 2x+yx+y+yx given that x=1 and y=2.
Step 1: Substitute x=1 and y=2 into the expression.
2(1)+21+2+21
Step 2: Simplify the first fraction.
2+23+21
43+21
Step 3: Find a common denominator and add the fractions.
The common denominator for 4 and 2 is 4.
43+2×21×2
43+42
43+2=45
The value of the expression is 45.
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Write 910ab×5abc27 in its simplified form and substitute the value to evaluate, given that c=2.
Step 1: Simplify the expression by canceling common factors.
910ab×5abc27=9×5×abc10×27×ab
Cancel numerical factors: 10/5=2, 27/9=3.
Cancel variable factors: ab/ab=1.
c2×3=c6
Step 2: Substitute c=2 into the simplified expression.
26=3
The simplified value is 3.
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Write 8xy3ab2×21ab216xy3 in its simplified form and substitute the values to evaluate, given that b=1 and y=2.
Step 1: Simplify the expression by canceling common factors.
8xy3ab2×21ab216xy3=8×21×xy×ab23×16×ab2×xy3
Cancel numerical factors: 3/21=1/7, 16/8=2.
Cancel variable factors: ab2/ab2=1, xy/xy=1, y3/y=y2.
7×11×2×y2=72y2
Step 2: Substitute b=1 and y=2 into the simplified expression. Note that b is no longer in the simplified expression.
72(2)2=72×4=78
The simplified value is 78.
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Write 3x−14ax+8x+6x−2a+2 in its simplified form and substitute the value to evaluate, given that x=−1 and a=2.
Step 1: Factor the numerators and denominators to simplify.
3x−14x(a+2)+2(3x−1)a+2
Step 2: Find a common denominator, which is 2(3x−1).
2(3x−1)4x(a+2)×2+2(3x−1)a+2
2(3x−1)8x(a+2)+(a+2)
Step 3: Factor out (a+2) from the numerator.
2(3x−1)(a+2)(8x+1)
Step 4: Substitute x=−1 and a=2 into the simplified expression.
2(3(−1)−1)(2+2)(8(−1)+1)
2(−3−1)(4)(−8+1)
2(−4)(4)(−7)
−8−28
Step 5: Simplify the fraction.
828=27
The simplified value is 27.
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Write 8m36m2n2+4mn2n3m2 in its simplest form and substitute the values to evaluate, given that m=3 and n=31.
Step 1: Simplify the first term.
8m36m2n2=836×mm2×n2=29mn2
Step 2: Simplify the second term.
4mn2n3m2=41×mm2×n2n3=41mn
Step 3: Add the simplified terms.
29mn2+41mn
Step 4: Substitute m=3 and n=31 into the expression.
29(3)(31)2+41(3)(31)
29(3)(91)+41(3)(31)
1827+123
Step 5: Simplify the fractions.
23+41
Step 6: Find a common denominator and add.
2×23×2+41=46+41=47
The simplified value is 47.
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Write 2xy+4y3x2+6x×9x22y in its simplified form and substitute the value to evaluate, given that x=1 and y=2.
Step 1: Factor the numerators and denominators.
2y(x+2)3x(x+2)×9x22y
Step 2: Cancel common factors.
Cancel (x+2) from numerator and denominator.
Cancel 2y from numerator and denominator.
Cancel 3x from 3x in the numerator and 9x2 in the denominator (3x/9x2=1/3x).
11×3x1=3x1
Step 3: Substitute x=1 and y=2 into the simplified expression. Note that y is no longer in the simplified expression.
3(1)1=31
The simplified value is 31.
That's 2 down. 3 left today — send the next one.