Answer:
d, To undo addition, you can use multiplication
Step-by-step explanation:
a, To remove a whole number next to the variable, multiply both sides by that number
41.8, angle y and the measurement angle labeled as just "138.2" are supplementary angles, meaning that when you add them together they equal 180. So all you have to do is subtract 138.2 from 180 and you get your answer which is 41.8.
To solve for this, set up a proportion.
21/40 = x/100.
Cross multiply the fraction's numerators with the denominators;
21 x 100, 40 and x.
2100/40x.
Divide both numbers by 40 to get x.
2100/40 = 52.5
21 is 52.5% of 40.
I hope this helps!
