Cat e (5×4)+(5×7) ? plss​

How to solve a simultaneous equation involved with fractions?

Find the magnitude, correct to two decimal places, made by each of the following with positive direction of the x axis a) y= x the answer is 45° but i don’t know how

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?