Answer:
Step-by-step explanation:
Given: Trey's test score average decreased by 14 points this semester.
To find: a signed number to represent this change in average.
Solution:
The decrease can be denoted by minus 
sign and increase can be denoted by plus 
sign.
So, a signed number to represent the change in test score average is
(2x+7)+(3x+58)=90
5x+65=90
5x=25
x=5
Ito's like the line BC is vertical and MN is horizontal as we compare both. So BC is perpendicular to MN and MN is also perpendicular To BC
We have the following expression:
2 (x + 4) ^ 2 = 6
Let's clear the value of x:
x + 4 = +/- root (6/2)
x + 4 = +/- root (3)
x = +/- root (3) - 4
The solutions are:
a = root (3) - 4
b = -raiz (3) - 4
Multiplying both solutions we have:
a.b = (root (3) - 4) * (- root (3) - 4)
a.b = -9 -4raiz (3) + 4raiz (3) + 16
a.b = -9 + 16
a.b = 7
Answer:
the exact value of a ⋅ b is 7
