Question

Complete the following activity to solve the simultaneous equations.
5x + 3y = 9 -----(I)
2x − 3y = 12 ----- (II)

Answer 1

5x + 3y = 9 -----(I)
2x − 3y = 12 ----- (II)

Adding equations (I) and (II)

5x + 3y = 9
2x − 3y = 12_
7x = 21
x = ${\displaystyle \frac{21}{7}}$

x = 3

Putting the value of x = 3 in (I) we get

5x + 3y = 9

5(3) + 3y = 9

15 + 3y = 9

3y = 9 − 15

3y = −6

y = ${\displaystyle \frac{-6}{3}}$

y = −2

Thus, (x, y) = (3, −2)