Question 1173247

y = 3x + 7

y = -4x + 21
<pre>y =   3x + 7 ----- eq (i)
y = - 4x + 21 ---- eq (ii)
0 = 7x - 14 ------ Subtracting eq (ii) from eq (i)
14 = 7x
{{{highlight_green(matrix(1,5, 14/7, "=", x, "=", 2))}}}
Now you can find y.