X=2-4y
3(2-4y)+8y=2 ⇒ 6-12y+8y=2
-4y=2-6=-4
y=1 ⇒ x=2-4*1=-2
Ответ:(-2;1)
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Y=8x-11, y=-6x+7
8x-11=-6x+7, 14x=18, x=9/7
y=8.9/7-11=72/7-11=72/7-77/7=-5/7
P(9/7, -5/7)
x/y=9/7):(-5/7)=-9/7.7/5=-9/5
1) (x-2,5)²=49
(x-2,5)²-7²=0
(x-2,5-7)(x-2,5+7)=0
(x-9,5)(x+4,5)=0
x=9,5 или x= -4,5
2) (3-2x)²=0,04
(3-2x)²-0,2²=0
(3-2x-0,2)(3-2x+0,2)=0
(2,8-2x)(3,2-2x)=0
x=1,4 или х=1,6
3) (5x+1)²=400
(5x+1)²-20²=0
(5x+1-20)(5x+1+20)=0
(5x-19)(5x+21)=0
x=19/5=3,8 или x=21/5=4,2
4) 2(y-1)²-2,42=0 |:2
(y-1)²-1,21=0
(y-1)²-1,1²=0
(y-1-1,1)(y-1+1,1)=0
(y-2,1)(y+0,1)=0
y=2,1 или y= -0.1
A) (m+4)(m-4) = m² -4² = m² - 16
b) (5n-p)(5n+p) = (5n)² -p² = 25n² - p²
в) (12a + 7b)(12a - 7b) = (12a)² - (7b)² = 144a² - 49b²
г) (10x⁴ - y²)(10x⁴ + y²) = (10x⁴)² - (y²)² = 100x⁸ - y⁴