We read your photo as:

Solve the following pairs of equations using the comparison method: (ii) 2x − 3y = 8 and (x+y)/(x−y) = 7/3. (v) x + y = 11 and y + 2 = (1/8)(10y + x).

Mathematics

ScanSolve AI Answer

Answers

3 parts
ii

x=295, y=65x = \frac{29}{5},\ y = \frac{6}{5}

iii

x=5, y=2x = 5,\ y = 2

iv

x=6, y=5x = 6,\ y = 5

Step-by-step solution

11 steps

Part ii· 4 steps

{2x−3y=8x+y=7\begin{cases} 2x - 3y = 8 \\ x + y = 7 \end{cases}
  1. Solve the second equation for xx.

    x+y=7x + y = 7
    x=7−yx = 7 - y

  2. Substitute x=7−yx = 7 - y into the first equation.

    2(7−y)−3y=82(7 - y) - 3y = 8
    14−2y−3y=814 - 2y - 3y = 8
    14−5y=814 - 5y = 8

  3. Solve for yy.

    −5y=8−14-5y = 8 - 14
    −5y=−6-5y = -6
    y=−6−5=65y = \dfrac{-6}{-5} = \dfrac{6}{5}

  4. Substitute y=65y = \dfrac{6}{5} into x=7−yx = 7 - y.

    x=7−65=355−65=295x = 7 - \dfrac{6}{5} = \dfrac{35}{5} - \dfrac{6}{5} = \dfrac{29}{5}

    x=295x = \dfrac{29}{5}, y=65y = \dfrac{6}{5}
    x = \frac{29}{5},\ y = \frac{6}{5}

Part iii

x=5, y=2x = 5,\ y = 2

{x+y=7x−y=3\begin{cases} x + y = 7 \\ x - y = 3 \end{cases}
  1. Add the two equations.

    (x+y)+(x−y)=7+3(x + y) + (x - y) = 7 + 3
    2x=102x = 10
    x=102=5x = \dfrac{10}{2} = 5

  2. Substitute x=5x = 5 into the first equation.

    5+y=75 + y = 7
    y=7−5=2y = 7 - 5 = 2

    x=5x = 5, y=2y = 2
    x = 5,\ y = 2

Part iv

x=6, y=5x = 6,\ y = 5

{x+y=11y+2=10y+x8\begin{cases} x + y = 11 \\ y + 2 = \dfrac{10y + x}{8} \end{cases}
  1. Multiply the second equation by 8 to eliminate the denominator.

    8(y+2)=10y+x8(y + 2) = 10y + x
    8y+16=10y+x8y + 16 = 10y + x

  2. Solve for xx.

    x=8y+16−10yx = 8y + 16 - 10y
    x=16−2yx = 16 - 2y

  3. Substitute x=16−2yx = 16 - 2y into the first equation.

    (16−2y)+y=11(16 - 2y) + y = 11
    16−y=1116 - y = 11

  4. Solve for yy.

    −y=11−16-y = 11 - 16
    −y=−5-y = -5
    y=5y = 5

  5. Substitute y=5y = 5 into x=16−2yx = 16 - 2y.

    x=16−2(5)x = 16 - 2(5)
    x=16−10=6x = 16 - 10 = 6

    x=6x = 6, y=5y = 5
    x = 6,\ y = 5

Was this helpful?

Try one yourself

A new problem that tests the same skill.

Still stuck on this one?

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

Got a different question?Ask your own question