Question

Помогите решить №3,4

Answer 1

a>3 b>8
4a>12
4a+b>12+8=20
4a+b>20

a>3 b>8
ab>3*8=24
ab-9>24-9=15
ab-9>15

a>3 b>8
a^2+b^2>3^2+8^2=73
a^2+b^2>73>60
a^2+b^2>60

a>3 b>8
(a+b)^2>(3+8)^2=121
(a+b)^2>121>100
(a+b)^2>100

x+y>8
x>8-y
2>x>8-y
2>8-y
y>8-2
y>6