There are two numbers which add up to 20. If one number is five more than four times the other, find the numbers.

  3 and 17

Step-by-step explanation:

Let x and y represent the numbers.

  x + y = 20 . . . . . . . . the numbers add up to 20

  x = 5 + 4y . . . . . . . . one number is 5 more than 4 times the other

Substituting the second equation into the first:

  (5 +4y) +y = 20

  5y = 15 . . . . . . . . . . subtract 5

  y = 3 . . . . . . . . . . . . divide by 5

  x = 20 -3 = 17

The numbers are 17 and 3.

second option

step-by-step explanation:

the measures of a triangle equal 180. use that to find x.

2x+3x+4x=180

9x=180

9x/9=180/9

x=20

now you know x, you know angle a is 40°, angle b is 60°, angle c is 80°.

because angle a is 40°, the first option doesn't work.

because angle b is 60°, the second option does work.

when you add angle a and b, you get 100°. complementary means it equals 90°, so the third option doesn't work.

when you add angle a and c, you get 120°, which is not 100.