Question

15
savon has 12 marbles, and her friend gives her some more. she now has 23 marbles all together. write an equation that represents m, the number of marbles her friend won and gave to savon.
16
kaitlyn buys a pack of socks for $6.79 and now has $321 left over. which equation represents the situation if x is the amount kaitlyn had before she bought the socks?
a) 6.79x = 321
b) x - 6.79 = 321
c) x + 6.79 = 321
d) 321 - x = 6.79
17
derek gives a cashier a 20 dollar bill to buy a personal pizza. he is given $8.74 as change. which equation represents the situation if c is the cost of the pizza?
a) c + 20 = 8.74
b) 20 - c = 8.74
c) 8.74c = 20
d) 8.74 - c = 20
18
julia has $36 to spend on books this week. after going to the store to buy books, she now has three dollars left over. which equation can be used to find b, the amount of money julia spent on books last week?
a) 3b = 36
b) \\(\frac{1}{3}b = 36\\)
c) b + 3 = 36
d) 36 - b = 3

1. choose the equation that represents the problem. (there are 2 that work. choose both.)

a
b
c
d

Explanation:

Step1: Solve Q15: Set up equation

$12 + m = 23$

Step2: Solve Q15: Isolate m

$m = 23 - 12$

Step3: Solve Q16: Identify correct equation

$x - 6.79 = 3.21$ (matches option B)

Step4: Solve Q17: Identify correct equation

$20 - c = 8.74$ (matches option B)

Step5: Solve Q18b: Identify correct equation

$36 - b = 3$ (matches option D)

Answer:

1. $m=11$
2. B) $x - 6.79 = 3.21$
3. B) $20 - c = 8.74$

18b. D) $36 - b = 3$