Answer:
x=40°
Step-by-step explanation:
(x-5)+(x+15)=90°
2x+10=90
2x=80
x=40°
Step-by-step explanation:

use the pattern


Apply FOIL method to multiply the parenthesis


Compare the expression with 
The value of a=7r and the value of b=5s
Answer :
a=7r , b=5s
The algebraic expressions would be a÷9
Answer:
Each one has 3 even and 3 odd numbers.
For the first one to be even there is a 3/6 probability, which reduces to 1/2.
The probability of the second one being even is also 1/2.
The probability of both being even would be 1/2 x 1/2 = 1/4 probability