Answer:
cos0 = 1
cos90 =0
so a for the first one and d for the other
C, because if you divided 75 by 100, you'd get .75, which is the same as three quarters.
Answer:
f. for the x values I think its -1 & 5
Option 1.
and option 4.
are equivalent to 
Step-by-step explanation:
Step 1:
The given expression is expanded as follows.
The -2 is multiplied with the 5x and then the -2 is multiplied with the
.
So the expression becomes as follows;

This is the first option given so the first expression is equivalent.
Step 2:

Of the other four options, only the fourth expression has the fraction
so the fourth expression is also equivalent.
Expressions 1 and 4 are equivalent to the given expression.
Answer:
$1260
Step-by-step explanation:
70/100 × $1800 = $1260