<span>1) 10-16x=8x-9
-16x-8x=-9-10
-24x=--19
<u>x=</u>2) 20-3x=2x-45
-3x-2x=-45-20
-5x=-65
<u>x=13</u>3) 2.7+1.9x=2x+1.5 </span>
1.9x-2x=1.5-2.7
-0.1x=-1.2
<u>x=12</u>
(4x-5)/(5x+2y)=1
4x-5=5x+2y
x=-5-2y
подставляем во2oe уравнение
(3-2x)/(1+4y)=1/5
15-10x=1+4y
10x+4y=14
10(-5-2y)+4y=14
y=-4; x=3;
(2/3*1/3-1)*1,5^2-1/4=(2/9-1)*1,5^2-1/4=(-7/9)*1,5^2-1/4=-7/9*(3/2)^2-1/4=-7/9*9/4-1/4=-7*1/4-1/4=-7/4-1/4=-2