We read your photo as:

Find the value of (7C3 + 7C6) / (7C3 - 7C6)

Mathematics

ScanSolve AI Answer

Step-by-step solution

5 steps

To find the value of the expression, we first need to calculate the values of the combinations.

  1. Calculate the value of 7C3_7C_3.

    The formula for combinations is nCr=n!r!(n−r)!_nC_r = \frac{n!}{r!(n-r)!}.

    7C3=7!3!(7−3)!=7!3!4!{_7C_3} = \frac{7!}{3!(7-3)!} = \frac{7!}{3!4!} 7C3=7×6×5×4!3×2×1×4!=7×6×53×2×1=2106=35{_7C_3} = \frac{7 \times 6 \times 5 \times 4!}{3 \times 2 \times 1 \times 4!} = \frac{7 \times 6 \times 5}{3 \times 2 \times 1} = \frac{210}{6} = 35
  2. Calculate the value of 7C6_7C_6.

    Using the combination formula:

    7C6=7!6!(7−6)!=7!6!1!{_7C_6} = \frac{7!}{6!(7-6)!} = \frac{7!}{6!1!} 7C6=7×6!6!×1=7{_7C_6} = \frac{7 \times 6!}{6! \times 1} = 7

    Alternatively, we can use the property nCr=nCn−r_nC_r = {_nC_{n-r}}, so 7C6=7C7−6=7C1=7_7C_6 = {_7C_{7-6}} = {_7C_1} = 7.

  3. Substitute the calculated values into the given expression.

    The expression is 7C3+7C67C3−7C6\frac{{_7C_3} + {_7C_6}}{{_7C_3} - {_7C_6}}.

    35+735−7\frac{35 + 7}{35 - 7}
  4. Perform the addition and subtraction in the numerator and denominator.

    4228\frac{42}{28}
  5. Simplify the fraction.

    Both the numerator and the denominator are divisible by 14.

    42÷1428÷14=32\frac{42 \div 14}{28 \div 14} = \frac{3}{2}

    The value of the expression is:

    \boxed{\textbf{\frac{3}{2}}}
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
Handwritten step-by-step solution preview

Handwritten Step-by-Step Solution

Get this as a handwritten image on WhatsApp — like a tutor wrote it for you.

Try on WhatsApp