Question

For the linear expression 3 - 4x: a. evaluate it if: i. x is 7; ii. x is -2; b. Find x if the expression is: i. equal to 19; ii. less than 23 (draw the graph); iii. at least -21 (draw the graph).

Answer 1

A)

Step 1: Problem

3 - 4x

Evalaute i) x = 7 ii) x = -2

Step 2: Concept

Substitute the value of x in the expression

Step 3: Method

i) x = 7

= 3 - 4x

= 3 - 4(7)

= 3 - 28

= -25

ii) x = - 2

= 3 - 4x

= 3 - 4(-2)

= 3 + 8

= 11

B)

Step 1:

i) 3 - 4x = 19

- 4x = 16 - 3

- 4x = 16

x = 16/-4

x = -4

ii) 3 - 4x < 23

-4x < 23 - 3

- 4x < 20

x > 20/-4

x > - 5

iii)