Question

If 5v–u=–2 and –v+9u=18 then the simultaneous solution of the given equation is:

Answer 1

−v + 9u = 18 → −v = 18 − 9u → v = 9u − 18


5v − u = −2 ∣ v = 9u − 18

5(9u − 18) − u = −2 ∣ expand and simplify

44u − 90 = −2 ∣ +90

44u = 88 ∣ ÷44

u = 2 ∣ v = 9u − 18

v = 9 × 2 − 18 = 18 − 18 = 0

So u = 2 and v = 0


(Hope that sort of made sense)

Answer 2

The solution is v = 0 and u = 2

Explanation:

`5v - u = -2 (1)\\-v + 9u = 18 (2)\\Multiply equation(2)by5toeliminatev\\-5v + 45u = 90 (3)\\\\Add equations (1) and (3)\\44u = 88 Divide both sides by 44\\(44u)/(44)=(88)/(44)\\\\u = 2\\\\Substitute u by 2 in the equation (1)\\5v - 2 = -2 Add 2 to both sides\\5v = 0\\v = 0\\\\The solution of the equation is v = 0 and u = 2`