3x^2 + 4x - 6 = 0
X1 + X2 = - 4 : 3 = - 1 ( 1/3 )
X1 * X2 = ( - 6 ) : 3 = - 2
(4x+5y)²=9y
(4x+5y)²<span>=9x
16x</span>²+20xy+25y²=9y
16x²+20xy+25y²=9x
9y=9x
y=x
*+72x+81=16x²+72x+81=(4x+9)²
a²+2×a×b+b²=(a+b)²
a²-?
b²=81
b=√81
b=9
2×a×b=72x|÷2
a×b=36x|÷b
a=36x÷b
a=36x/9
a=4x
a²=(4x)²
a²=16x²