Transcript Solving 2-step Equations

Solving 2-step Equations
Algebra 1 – Mrs. Puccio
1.
9 + 4k = 1
9
9
4
4k = -8
4
4
k = -2
Isolate k.
Cancel 9.
Cancel 4.
2.
6b – 7 = 17
+7 +7
66b = 24
6
6
b=4
Isolate b.
Cancel - 7.
Cancel 6.
3.
13 = 3 + 2n
3 3
Isolate n.
Cancel 3.
10 = 2
2n
2
2
Cancel 2.
5=n
n=5
4.
2 – 7c = 23
2
2
-7
-7c = 21
-7
-7
c = -3
Isolate c.
Cancel 2.
Cancel -7.
5.
8 – m = 36
8
8
Isolate m.
Cancel 8.
- m = 28
Rewrite with
coefficient.
-1
-1m = 28
-1
-1
Cancel -1.
m = -28
6. 0.5y + 1 = 6.5
5y + 10 = 65
 10  10
5
5y = 55
5
5
y = 11
Mult. Eq. by 10.
Isolate y.
Cancel + 10.
Cancel 5.
7.
Isolate t.
41 = -10t + 1
1
1 Cancel + 1.
40 = -10
-10t
-10 -10
-4 = t
t = -4
Cancel -10.
8.
x + 6 = 10
3
6 6
x
3( ) = ( 4)3
3
x = 12
Isolate x.
Cancel + 6.
Cancel 3.
9.
7+n = -8
4
Isolate n.
7+n = -8
4(
) ( )4
4
Cancel 4.
7 + n = -32
-7
-7
Cancel 7.
n = -39
a
10. 10 – 7 = 12
10
10
a
-7 ( - ) = ( 2)(-7)
7
a = -14
Isolate a.
Cancel 10.
Cancel -7.
2
11. 5 – 3 m = 13
5
5
Isolate m.
Cancel 5.
4
2
3
2
3
Cancel
.
m
=
8
- (
) ( )(- )
3
2
2 3
1
1
m = -12
12.
Find three consecutive
integers whose sum is 42.
first:
second:
third: +
sum:
x
-15 + 1
x+1
-15 + 2
x+2
3x + 3 = -42
- 3 -3
3 = -45
3x
3
3
x = -15
-15
-14
-13
Answer:
-15, -14, -13
13.
Find two consecutive odd
integers whose sum is 38.
first:
x
second: + x + 2
sum:
18 + 2
18
20
2x + 2 = 38
- 2 -2
2 = 36
2x
2
2
x = 18
Answer:
18, 20
14.
Find three consecutive even integers such
that the sum of the first and last is -34.
first:
second:
third:
last:
first + last
x
x+2
x+4
x+6
-20 + 2
-20 + 4
-20 + 6
x + x + 6 = -34
2x + 6 = -34
- 6 -6
2x = -40
2
2
2
x = -20
-20
-18
-16
-14
Answer:
-20,-18,-16,-14