Question

solve this by substitution method.
11x+15y+23=0
7x-2y-20=0

Answer 1

11x + 15y + 23 = 0 ---------------------(1)
7x - 2y - 20 = 0  -------------------(2)
2y = 7x - 20
y = 7x/2 - 10        put in equation (1)
11x + 105x/2 -150 + 23 = 0
127x/2 - 127 = 0
x = 2    put in equation (2)
14 - 2y - 20 = 0
y = -3

Answer 2

Answer:

x = 2 and y = -3.

Step-by-step explanation:

Given Equation:-

11x + 15y = -23                     ......(i)

7x - 2y = 20                         ......(ii)

Multyplying (i) by 2 and (ii) by 15 and adding the result, we get

⇒ 22x + 105x = -46 + 300

⇒ 127x = 254

⇒ x = $\frac{254}{127}$ = 2.

Putting x = 2 in eq (i), we get

⇒ 11(2) + 15y = -23

⇒ 22 + 15y = -23

⇒ 15y = -23 - 22

⇒ 15y = -45

⇒ y = $\frac{-45}{15}$

⇒ y = -3.

Hence, x = 2 and y = -3.