Question

Solve 3x+2y=7 and x-4y=-21 by using any method

Answer 1

Answer:

(- 1, 5 )

Step-by-step explanation:

Using the method of substitution.

Given the 2 equations

3x + 2y = 7 → (1)

x - 4y = - 21 → (2)

Rearrange (2) expressing x in terms of y by adding 4y to both sides.

x = 4y - 21 → (3)

Substitute x = 4y - 21 into (1)

3(4y - 21) + 2y = 7 ← distribute and simplify left side

12y - 63 + 2y = 7

14y - 63 = 7 ( add 63 to both sides )

14y = 70 ( divide both sides by 14 )

y = 5

Substitute y = 5 into (3)

x = (4 × 5) - 21 = 20 - 21 = - 1

Solution is (- 1, 5 )