Question

-2x = 16–8y x+4y= 25 Solve by substitution

Answer 1

Answer:

($\frac{17}{2}$, $\frac{33}{8}$

Step-by-step explanation:

Given the 2 equations

- 2x = 16 - 8y → (1)

x + 4y = 25 → (2)

Rearrange (2) expressing x in terms of y by subtracting 4y from both sides

x = 25 - 4y → (3)

Substitute x = 25 - 4y into (1)

- 2 (25 - 4y) = 16 - 8y ← distribute left side

- 50 + 8y = 16 - 8y ( add 8y to both sides )

- 50 + 16y = 16 ( add 50 to both sides )

16y = 66 ( divide both sides by 16 )

y = $\frac{66}{16}$ = $\frac{33}{8}$

Substitute this value into (3) for corresponding value of x

x = 25 - 4 × $\frac{33}{8}$ )

  = $\frac{50}{2}$ - $\frac{33}{2}$ = $\frac{17}{2}$

Solution is ( $\frac{17}{2}$, $\frac{33}{8}$ )