80x-30-21x-7=140
59x-37=140
59x=140+37
x=177/59
x=3
(a+7)^2-(3a-4)(3a+4)=a^2+14a+49-9a^2-16=-8a^2+14a+35
80x-30-21x-7=140
59x-37=140
59x=140+37
x=177/59
x=3
(a+7)^2-(3a-4)(3a+4)=a^2+14a+49-9a^2-16=-8a^2+14a+35