Please some-one help, I can't fail this test again and I can't figure this out. Please some-one help

Which of these tables represents a non-linear function?

Present age of man is 45 years, 5 years back his age was 4 times age of his son what is present age of his son?

The measures of the angles in △abc are given by the expressions in the table. angle measure angle a 65° angle b (3x−10)° angle c (2x)∘ find the value of x. then find the m∠b and m∠c.