Lesson 1.2.2
1-52. See below:
a. Multiply 7 by 215 to get 1505 cranes, and then multiply 10
by 215 to get 2150 minutes. 2150 minutes. 35.8 hours.
b. Possible strategies are presented in problem 1-53 below.
1-53. See below:
a. Look for something that multiplied by 7 will equal 1505; to
find the value, work backwards:1505 ÷ 7 = 215; then, use this
as both the numerator and denominator of the 1,
. x=
2150.
b. The ratios are still equal because both sides are changed the
same way. Both sides are multiplied by 1505 because x is
divided by 1505. x =
= 2150.
c. Yes, both sides of the equation can be multiplied by 7 and
1505. This eliminates the fractions and makes the equation
simpler, but x is not yet isolated on one side of the
equation. Divide by 7. x = 15050 ÷ 7 = 2150
• 1-54. See below:
a.
= x, x ≈ 20.1 cm
b. Possible answer:
, 15 · 1600 = 80x, x = 300
c.
, x = 33
• 1-55. 50 · x = 0.8 · 1240, x = 19.84 kg
• 1-56. Using Fraction Busters will result in the equation 7 · 4 ·
4 · 7 which simplifies to what Juana got: 7 · 10 = x · 4
1-57. a: 20
b: 2 17
1-58. Number of Letters: 15, 42
Answers Core Connections, Course 3
·
c: 13 13 hours
Cost of Stamps: $3.15, $0.45, $225.00
1
Number of Students
1-59.
Hours of Sleep
1-60. Todd is 37 years old, while Jamal is 27 years old.
1-61. a: − 17
24
d: −
2
4
3
b: 4.1
= −1 13
e:
43
12
7
= 3 12
c:
21
15
=
7
5
= 1 25
f: 2.24
Core Connections, Course 3