1) (2 + m)² = 5² + 2•5m + m² = 5² + 10m + m²
2) (2c - d)² = 4c² - 2•2c5d + d² = 4c² - 20cd +d²
3) (3p + 4k)² = 9p² + 2•3p4k + 16k² = 9p² + 24pk +
+ 16k²
4) (6a + 5x)² = 36a² + 2•6a5x + 25x² = 36a² + 60ax++ 25x²
5) (5y - 4x)² = 25y² - 2•5y4x + 16x² = 25y² - 40yx + + 16x²
(7х^2-5x+3)-(5x^2-4)=7x^2-5x+3-5x^2+4=2x^2-5x+7=(x-3,5)(x+1)
2x^2-5x+7=0
D=b^2-4ac(a=2, b=-5, c=7)
D=25+56=81=9^2
x1=5+9:4=14:4=3,5
ч2=5-9:4=-4:4=-1
1/2x=2+2/3y
-1/4x+1/3y=-1
x=4+4/3y
-1/4(4+4/3y)-1/3y=-1
x=4+4/3y
-1-1/3y-1/3y=-1
x=4+4/3y
2/3y=-1+1
x=4+4/3y
2/3y=0
x=4+4/3y
y=0
x=4
y=0