A)-36c -3.(5-6c)ˇ2 = -36c -3.(25-60c +36cˇ2)=-36c-75+180c-108cˇ2=
= 144c-75-108cˇ2
b)(7b-1)(1+7b)-b(4-3b)=49bˇ2-1-4b+3bˇ2 = 52bˇ2-4b-1
c)(2k-3).(3+2k) - (3k-5)ˇ2 -30k=4kˇ2-9-9kˇ2+30k-25-30k=-5kˇ2-34
2)(3y+1)ˇ2-9.(y+1)(y-1)=8y-16
9yˇ2 +6y +1 -9yˇ2+9=8y-16
6y+10 = 8y-16
2y= 26, y = 13