А+8=а+8=)=)=)=):D:D:D:D:D:D
1) 16с^2=49
с^2=49/16
с1=7/4
с2=-7/4
2) 16х^2-9-16х^2+1=3х
-8=3х
х=-8/3
<span>1) 3a(a+2)-(a+3)²= 3a(a+2)-(a+3)(a+3)=3a²+6a-(a²+6a+9)=2a²-9</span>
<span><span>2) 3(y-1)²+6y = 3(y-1)(y-1)+6y=3(y²-2y+1)+6y=3y²-6y+3+6y=3y²+3=3(y²+1)</span></span>
<span><span><span>3) 8c+4(1-c)² = 8c+4(1-2c+c²)=8c+4-8c+4c²=4(c²+1)</span></span></span>
<span><span><span><span>4) 4ab+2(a-b)</span>² = 4ab+2(a²-2ab+b²)=4ab+2a²-4ab+2b²=2(a²+b²)</span></span></span>
<span><span><span><span>5) 3(x+y)²-6xy = 3(x²+2xy+y²)-6xy=3x²+6xy+3y²-6xy=3(x²+y²)</span></span></span></span>