A man earns $8480 per month. He spends 1/4 of it on house rent, 3/8 on food and clothes, 1/10 on insurance and 1:5 on other items. he saves the rest. How much does he save every month

Explanation:

I'm assuming you meant to write 1/5 instead of 1:5

Add up all the fractions

1/4 + 3/8 + 1/10 + 1/5

20/80 + 30/80 + 8/80 + 16/80

(20+30+8+16)/80

74/80

37/40

He spends 37/40 of his income on rent, foot, clothes, insurance and other items combined.

Subtract this from 1 to find the fraction of his income he saves

1 - 37/40

40/40 - 37/40

(40-37)/40

3/40

He saves 3/40 of his monthly income.

(3/40)*8480 = 636 dollars is the amount saved every month.

because linear equations are a lot simpler than quadratics equations, and linear equations formula is a lot easier to memorize. that's why i think they're harder.