Question 134802
{{{3b - a = -7}}}
{{{5a + 6b = 14}}}
First get them both in the order {{{a}}} first, {{{b}}} second
{{{-a + 3b = -7}}}
{{{5a + 6b = 14}}}
Multiply the 1st equation by 5 and add the equations
{{{-5a + 15b = -35}}}
{{{5a + 6b = 14}}}
{{{21b = - 21}}}
{{{b = -1}}} answer
{{{3b - a = -7}}}
{{{3*(-1) - a = -7}}}
{{{-a = -4}}}
{{{a = 4}}} answer
check:
{{{3b - a = -7}}}
{{{3*(-1) - 4 = -7}}}
{{{-3 - 4 = -7}}}
{{{-7 = -7}}}
{{{5a + 6b = 14}}}
{{{5*4 + 6*(-1) = 14}}}
{{{20 - 6 = 14}}}
{{{14 = 14}}}
OK