Answer:
Step-by-step explanation:
She added 3x and -2x, getting 5x, instead of x. She needs to pay more attention to the positive/negative signs.
Answer:
B=45
Step-by-step explanation:
let the supplamentary angle of <A is <d
180-A=d
180-135=d
45=d
90+d+B=180
90+45+B=180
135+B=180
B=180-135
B=45
C/30 = 8/12
c/30 = 2/3
3c = 60
c = 60/3
c = 20
Answer:

Step-by-step explanation:
we know that
<u><em>Combinations</em></u> are a way to calculate the total outcomes of an event where order of the outcomes does not matter.
To calculate combinations, we will use the formula

where
n represents the total number of items
r represents the number of items being chosen at a time.
In this problem

substitute

simplify


