Answer:
a = -10
Step-by-step explanation:
<span>To evaluate the given expression, we need the values of each variable and substitute these values to the expression. Then, go on with the operations involved.
</span>4x - y - 2z
4(-2) - (3) - 2(-2)
-8 - 3 + 4
-7
To solve this, you would divide the miles by the number of hours, 21 / 4
21 divided by 4 equals 5.25
All angles are of triangle and thus give sum of 180⁰
x + 5 + 7x - 5 + x = 180⁰
9x = 180⁰
x = 20⁰
