There is a value of $a$ such that subtracting $a-4$ from $4a+16$ gives an answer of $-25$. what is that value of $a$?

a = -15

Step-by-step explanation:

Let's rewrite the exercise in math language.

We have to subtract a-4 from 4a+16 to get -25, that is

4a+16 - (a-4) = -25

The minus sign that is just before the parenthesis changes all the signs inside it. Therefore, if we want to delete the parenthesis, we need to change the signs before.

4a + 16 - a + 4 = -25

Now we can associate the terms with an a between them and the terms without it from the left side of the equation.

3a + 20 = -25

Let's subtract 20 on both sides.

3a + 20 - 20 = -25 - 20

3a = -45

Finally, we divide by 3 on both sides

3a/3 = -45/3

a = -15

step-by-step explanation:

ok so im not 100% sure but you would start by adding 5.1t and 1.9t beacuse they have the same variable. that is 7t.   then add -3.6 + 1.2 which is -2.4

so then keep that as -2.4 + 7t. i apologize if this is incorrect. best luck on your test < 3

21

step-by-step explanation: