Question

Work out the value of the expression when a = −3, b = 4, c = −2
20a − 2c^2 − 3b

Answer 1

Step-by-step explanation:

Starting with the second given equation;

3a + 5b + 7c = 30

(2a + 3b + 4c) + (a + 2b + 3c) = 30

35 + (a + 2b + 3c) = 30

a + 2b + 3c = -5______(1)

Now, using the first equation

2a + 3b + 4c = 35

( a + 2b + 3c) + (a + b + c)=35

-5 +(a + b + c)=35 [ using__(1)]

a + b +c=40

Answer 2

Answer:

20×(-3) -2(-2)^2-3×4

-60-8-12

-60-20

-80