Answer:
Grandfather age = 20 * 4 = 80
Step-by-step explanation:
Let Elena age be x
grandfather age is 4x
x + 4x = 100
5x = 100
x = 100/5 = 20 = Elena age
E=3(6)^2
3(36)
=108
Therefore E=108
Answer:

Step-by-step explanation:




but if

then since


so

or





Answer:
The equation of line is: 
Step-by-step explanation:
We need to find an equation of the line that passes through the points (-6, -2) and (-3, 2)?
The equation of line in slope-intercept form is: 
where m is slope and b is y-intercept.
We need to find slope and y-intercept.
Finding Slope
Slope can be found using formula: 
We have 
Putting values and finding slope

So, we get slope: 
Finding y-intercept
Using point (-6,-2) and slope
we can find y-intercept

So, we get y-intercept b= 6
Equation of required line
The equation of required line having slope
and y-intercept b = 6 is

Now transforming in fully reduced form:

So, the equation of line is: 
Answer:
x=3
Step-by-step explanation:
2x-x=5-3+1
x=3
I think that's it