Question

Choose the value of X that makes the open sentence true

30 - x^2 < 3x + 7

A 4
B 3
C 2
D 1

Answer 1

a 30- 16=14 3*4+7=19 14<19 correct
b 30-9=21 3*3+7=16 21>16 incorrect
c 30-4=26 3*2+7=13 26>13 incorrect
d 30-1=29 3*1+7=10 29>10 incorrect

the answer is a

Answer 2

Option A - 4

Explanation:

Given : Inequality
`30 - x^2 < 3x + 7`

To find : Choose the value of x that makes the open sentence true ?

Solution :

We substitute the value of x from options to check which is true,

A) x=4

`30 - 4^2 < 3(4) + 7`

`30-16 < 12+ 7`

`14< 19`

It is true.

B) x=3

`30 - 3^2 < 3(3) + 7`

`30-9< 9+ 7`

`21< 16`

It is false.

C) x=2

`30 - 2^2 < 3(2) + 7`

`30-4<6+ 7`

`26< 13`

It is false.

D) x=1

`30 - 1^2 < 3(1) + 7`

`30-1<3+ 7`

`29< 10`

It is false.

Therefore, Option A is correct.