80% of a number is x.
What is 40% of that same number?

Step-by-step explanation:

ntroduction. Percent, p%

'Percent (%)' means 'out of one hundred':

p% = p 'out of one hundred',

p% is read p 'percent',

p% = p/100 = p ÷ 100

80% = 80/100 = 80 ÷ 100 = 0.8

100% = 100/100 = 100 ÷ 100 = 1

Percentage of 80% of what number = 40?

80% of what number = 40 is equivalent to:

80% × ? = 40

80% × ? = 40

? =

40 ÷ 80% =

40 ÷ (80 ÷ 100) =

(100 × 40) ÷ 80 =

4,000 ÷ 80 =

50

check above link.

graphically?   well, you graph them both, the solutions is where they both intersect each other, since there are two solutions, meaning they will meet twice, or namely the linear will run into the quadratic curve twice, and where they meet, those x,y coordinates are the solutions to the system.