Solve and verify each of the following systems of linear equations 4y=3x+7 and 9x+4y-139=0

Rearranging the first equation:-

3x - 4y = - 7

9x + 4y = 139

12x = 132

x = 132/12 = 11

Substituting fro x in the second equation:-

9 (11) + 4y = 139

4y = 139 - 99 = 40

y = 40/4 = 10

Answer x = 4, y = 10.