Question

solve and check help plezz
2x+5<8 the answer is x<3/2 how do i check this??

Answer 1

mathway.com

Answer 2

your answer is correct

Answer 3

yes i kno but i have to provide the check thing

Answer 4

can u help?

Answer 5

2x + 5 < 8
2x < 8 - 5
2x < 3
x < 3/2
now we know that x is less then 3/2...so pick a number less then 3/2 (1 1/2) such as 1 1/4, which is 5/4
now sub 5/4 in for x in the inequality to see if it is true

2x + 5 < 8
2(5/4) + 5 < 8
5/2 + 5 < 8
5/2 + 10/2 < 8
15/2 < 8
7 1/2 < 8 (correct)

Answer 6

if you picked a number greater then 8, then the inequality would be false.

Answer 7

oops...picked a number greater then 3/2, it would be incorrect

Answer 8

so instead of 7 1/2<8 it should be 3/2?

Answer 9

the 7 1/2 < 8 was my way of checking that the inequality was true when subbing in 5/4, a number less then 3/2.

Answer 10

you should be able to sub in any number less then 3/2 for the inequality to be correct.

Answer 11

ohh i see. i have another question how wud i check x^2-3x+5=x(x-6)+20 my answer is x=5

Answer 12

you would check it by subbing in 5 for x

x^2 - 3x + 5 = x(x - 6) + 20
5^2 - 3(5) + 5 = 5(5 - 6) + 20
25 - 15 + 5 = 5(-1) + 20
30 - 15 = -5 + 20
15 = 15 (correct)

they equal and you checked it by subbing in 5 for x

Answer 13

any questions ?

Answer 14

okay i have 2 more. god ur a life savor. 3x+4>10 my answer is x>2