Question

Reasoning Solve the system of linear equations using substitution. Use pencil and paper. Which expression would be easier to substitute into the other​ equation, in order to solve this​ problem? Explain your reasoning. x = 4y - 2 x + 4y =7

Answer 1

x = 5 /2 , y = 9 / 8

Explanation:

x = 4y - 2 ....... (i)

x + 4y =7 ....... (ii)

Substituting eqn (i) into eqn (ii);

(4y - 2 ) + 4y = 7

4y - 2 + 4y = 7

8y = 7 + 2 = 9

y = 9 / 8

substitute y = 9 / 8 in eqn (i)

x = 4 (9 / 8) - 2

x = 9 / 2 - 2

x = (9 - 4 ) / 2

x = 5 / 2