i. First simplify the following expressions, then determine the value of the expression by substituting a = 7.
a. 13a+2a—5a b. 3a+7a
c. 17 +5a+3a d. 6a—a+2
a. 13a + 2a - 5a
Combine like terms:
= (13 + 2 - 5)a
= 10a
Substitute a = 7:
= 10(7)
= 70
b. 3a + 7a
Combine like terms:
= 10a
Substitute a = 7:
= 10(7)
= 70
c. 17 + 5a + 3a
Combine like terms:
= 17 + 8a
Substitute a = 7:
= 17 + 8(7)
= 17 + 56
= 73
d. 6a - a + 2
Combine like terms:
= 5a + 2
Substitute a = 7:
= 5(7) + 2
= 35 + 2
= 37
a. Simplify 13a + 2a - 5a:
Combine like terms:
(13 + 2 - 5)a = 10a
Now substitute a with 7:
10(7) = 70
b. Simplify 3a + 7a:
Combine like terms:
(3 + 7)a = 10a
Now substitute a with 7:
10(7) = 70
c. Simplify 17 + 5a + 3a:
Combine like terms:
17 + (5 + 3)a = 17 + 8a
Now substitute a with 7:
17 + 8(7) = 17 + 56 = 73
d. Simplify 6a - a + 2:
Combine like terms:
(6 - 1)a + 2 = 5a + 2
Now substitute a with 7:
5(7) + 2 = 35 + 2 = 37