All the solutions provided in McGraw Hill Math Grade 5 Answer Key PDF Chapter 2 Lesson 2 Relating Addition and SubtractionÂ are as per the latest syllabus guidelines.

Use inverse operations to solve.
Question 1.
17 + 48 = 65
65 – 48 = 17
17 + 48 = 65.
65 – 48 = 17.

Explanation:
17 + 48 = 65.
A + B = C.
=> C – B = A.
=>65 – 48 = 17.

Question 2.
39 – 18 = 21
21 + 18 = ____
39 – 18 = 21.
21 + 18 = 39.

Explanation:
39 – 18 = 21.
A + B = C.
=> C – B = A.
=> 21 + 18 = 39.

Question 3.
64 + 83 = ___
147 – 83 = ____
64 + 83 = 147.
147 – 83 = 64.

Explanation:
64 + 83 = 147.
A + B = C.
=> C – B = A.
=>147 – 83 = 64.

Question 4.
56 – 27 = 29
29 + 27 = ____
56 – 27 = 29.
29 + 27 = 56.

Explanation:
56 – 27 = 29.
A + B = C.
=> C – B = A.
=> 29 + 27 = 56.

Question 5.
79 + 40 = 119
119 – 40 = ___
79 + 40 = 119.
119 – 40 = 79.

Explanation:
79 + 40 = 119.
A + B = C.
=> C – B = A.
=> 119 – 40 = 79.

Question 6.
82 – 58 = ____
24 + 58 = ____
82 – 58 = 24.
24 + 58 = 82.

Explanation:
82 – 58 = 24.
A + B = C.
=> C – B = A.
=> 24 + 58 = 82.

Question 17.
71 + 57 = 128
128 – 57 = ____
71 + 57 = 128.
128 – 57 = 71.

Explanation:
71 + 57 = 128.
A + B = C.
=> C – B = A.
=> 128 – 57 = 71.

Question 18.
79 – 41 = 38
38 + 41 = ____
79 – 41 = 38.
38 + 41 = 79.

Explanation:
79 – 41 = 38.
A + B = C.
=> C – B = A.
=> 38 + 41 = 79.

Question 9.
78 + 56 = ____
134 – 56 = ____
78 + 56 = 134.
134 – 56 = 78.

Explanation:
78 + 56 = 134.
A + B = C.
=> C – B = A.
=> 134 – 56 = 78.

Question 10.
Teddy wants to know the value of x in 49 + x = 56. He knows the difference of 56 and 49 is 7. How can he find the value of x? Explain.
The value of x in equation 49 + x = 56 can be solved by using subtraction.
=> x = 7.

Explanation:
value of x in 49 + x = 56:
49 + x =56
=> xÂ  = 56 – 49
=> x = 7.

Question 11.
Teresa wants to find the difference of 136 and 117. She knows the sum of 117 and 19 is 136. How can she find the difference? Explain.