1.
а) -3y - 7 = 2y - 8
-3y - 7 = 2y - 8
-3y - 7 + 7 = 2y - 8 + 7
-3y = 2y - 1
-3y - 2y = 2y - 1 - 2y
-5y = -1
-5y/-5 = -1/-5
y = 1/5
б) -4 + 10x = 2x - 11
-4 + 10x + 4 = 2x - 11 + 4
10x = 2x - 7
10x - 2x = 2x - 7 - 2x
8x = -7
8x/8 = -7/8
x = -(7/8)
в) 2x - 14 = 6 - 2x
2x - 14 + 14 = 6 - 2x + 14
2x = -2x + 20
2x + 2x = -2x + 20 + 2x
4x = 20
4x/4 = 20/4
x = 5
2.
а)1.24x * 100 + 3.46 * 100 = 1,76x * 100 = 1.76x * 100 + 6.58 * 100
124x + 346 = 176x + 658
124x + 346 - 346 = 176x + 658 - 346
124x = 176x + 312
124x - 176x = 176x + 312 - 176x
-52x = 312
-52x/52 = 312/-52
x = -6
б)-5y - 5.12 = -0.88 - y
-5y - 5.12 + 5.12 = -0.88 - y + 5.12
-5y = -y + 4.24
-5y + y = -y + 4.24 + y
-4y = 4.24
-4y/-4 = 4.24/-4
y= -1.06
3.
3 - 2 = 1, на столько 3 больше 2
1 : 2 * 100% = 50%, на столько 3 больше 2
4.
3 - 2 = 1, на столько 2 меньше 3
1 : 3 * 100% = 33 1/3 %, на столько 2 меньше 3.