4.
9х(х+6)-(3х+1)²=1
9х²+54х-9х²+6х-1=1
60х=1+1
60х=2
х=2:60
х=1/30
5.
(12а³-7х)( -12а³-7х)=(12а³-7х)(12а³+7х)=144а⁶-49х²
( -11х-7у)²=(11х+7у)²=121х²+154ху+49у²
6.
(х+6)²-(х-5)(х+5)=79
х²+12х+36-х²+25=79
12х=79-36-25
12х=18
х=18:12
х=3/2=1 1/2=1,5
9х²-4=0
(3х-2)(3х+2)=0
3х-2=0
3х=2
х1=2/3
3х+2=0
3х= - 2
х2= - 2/3
7.
81m⁴p²-25n⁶=(9m²p-5n³)(9m²p+5n³)
(3с-5)²-16с²=(3с-5-16с)(3с-5+16с)=(-5-13с)(-5+18с)=25-90с+65с-234с²=25-25с-234с²