Question

lesson 5 practice problems
1 write each subtraction equation as an addition equation.
a. $5 - 8 = a$
b. $-30 - 20 = p$
c. $7 - (-10) = x$
d. $-12 - (-15) = z$
2 find each difference. if you get stuck, consider drawing a number line diagram.
a. $9 - 4$
b. $4 - 9$
c. $9 - (-4)$
d. $-9 - (-4)$
e. $-9 - 4$
f. $4 - (-9)$
g. $-4 - (-9)$

Explanation:

Problem 1:

Part a:

Step 1: Recall the rule \(a - b=a+(-b)\)

Given \(5 - 8=a\), using the rule, we rewrite it as \(5+(-8)=a\)

Part b:

Step 1: Apply \(a - b=a+(-b)\)

For \(- 30-20 = p\), we get \(-30+(-20)=p\)

Part c:

Step 1: Use the rule \(a-(-b)=a + b\)

Given \(7-(-10)=x\), rewrite it as \(7 + 10=x\)

Part d:

Step 1: Apply \(a-(-b)=a + b\)

For \(-12-(-15)=z\), we get \(-12 + 15=z\)

Problem 2:

Part a:

Step 1: Subtract the numbers

\(9-4=5\)

Part b:

Step 1: Use \(a - b=a+(-b)\)

\(4-9=4+(-9)=- 5\)

Part c:

Step 1: Apply \(a-(-b)=a + b\)

\(9-(-4)=9 + 4=13\)

Part d:

Step 1: Use \(a-(-b)=a + b\)

\(-9-(-4)=-9 + 4=-5\)

Part e:

Step 1: Rewrite as addition

\(-9-4=-9+(-4)=-13\)

Part f:

Step 1: Apply \(a-(-b)=a + b\)

\(4-(-9)=4 + 9=13\)

Part g:

Step 1: Use \(a-(-b)=a + b\)

\(-4-(-9)=-4 + 9=5\)

Answer:

Problem 1:

a. \(5+(-8)=a\)
b. \(-30+(-20)=p\)
c. \(7 + 10=x\)
d. \(-12 + 15=z\)

Problem 2:

a. \(5\)
b. \(-5\)
c. \(13\)
d. \(-5\)
e. \(-13\)
f. \(13\)
g. \(5\)