Solve the simultaneous equations 2x - 3y + 10,  10x - 6y = - 5

Solve the simultaneous equations 2x - 3y + 10, 10x - 6y = - 5

Mathematics

JAMB 1985

Solve the simultaneous equations 2x - 3y + 10, 10x - 6y = - 5

A. x = 2\(\frac{1}{2}\), y = 5
B. x = \(\frac{1}{2}\), y = \(\frac{3}{2}\)
C. x = 2\(\frac{1}{4}\), y = 3\(\frac{1}{2}\)
D. x = 2\(\frac{1}{3}\), y = 3\(\frac{1}{2}\)
E. x = 2\(\frac{1}{3}\), y = 2\(\frac{1}{2}\)

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Correct Answer: Option A

Explanation

2x - 3y = - 10; 10x - 6y = -5

2x - 3y = -10 x 2

10x - 6y = -5

4x - 6y = -20 .......(i)

10x - 6y = -5.......(ii)

eqn(ii) - eqn(1)

6x = 15

x = \(\frac{15}{6}\)

= \(\frac{5}{2}\)

x = 2\(\frac{1}{2}\)

Sub. for x in equ.(ii) 10(\(\frac{5}{2}\)) - 6y = -5