I'm assuming you meant to write a^4 = 625.
If that is the case, then note how 625 = 25^2, and how a^4 is the same as (a^2)^2
So we go from this
a^4 = 625
to this
(a^2)^2 = 25^2
Apply the square root to both sides and you'll end up with: a^2 = 25
From here, apply the square root again to end up with the final answer: a = 5 or a = -5
As a check:
a^4 = (-5)^4 = (-5)*(-5)*(-5)*(-5) = 25*25 = 625
a^4 = (5)^4 = (5)*(5)*(5)*(5) = 25*25 = 625
Both values of 'a' work out
You should use the ratio so
2/ 4 = 6.5 / n
n= 6.5 x 4 / 2 = 13 inches
2- for two hours ------> four inches of snow
for x hours -----> y inches of snow
the equation is
2/4 = x/ y
x= 2y / 4
for x is the hours and y is the inches
exercice 2
5 gr granula ----------------------> 1750 calories
2 gr granula ----------------------> n ?? calories
by cross multiplication
n = 2 x1750 / 5 = 700 calories .
2-
she wants to eat 175 calories so
u put granula under granula and calories under calories to make this cross
<span>5 gr granula ----------------------> 1750 calories
</span>??? m granula ---------------------> 175 calories
<span>by cross multiplication </span>
m = 175 x 5 / 1750 = 0.5 gr of granula
I would use elimination. I would multiply 4x+3y=2 by 3 so the it becomes 12x+9y=6, and I would multiply the bottom equation by 4 so that it becomes 12x+8y=4. Because I am using elimination I have to get rid of one variable, I chose to get rid of X hence that the coefficient of X in each equation is now 12. i simply subtract both equations and get y by itself. y=2. I plug in Y to find x in either of the original equations, where I get x=-1. To check my work substitute the values of x and y in the other equation. 4(-1)+3(2)=2 -------> 2=2
-3.5, negative 1 over 4, 1 over 3, 2
