SAT PREP 2015

Question

If f(x)= x^2+3x+5 and g(x) = 3x^2, what is the value of ƒ(-2)/ g(-1)

 

 

*The slash means over. Like 1 over 2 (fraction) 

Answer 1

The way to solve this is to plug in -2 into f(x) and -1 into g(x). Then divide. 

 

f(x)= x^2+3x+5

f(-2) = ((-2)^2) + 3(-2) + 5

f(-2) = 4 + (-6) + 5

f(-2) = 4 - 6 + 5 = 3

f(-2) = 3

 

g(x) = 3x^2

g(-1) = 3(-1)^2

*PEMDAS: exponent first!

g(-1) = 3(1) = 3

g(-1) = 3

 

Now we just substitute!

ƒ(-2)/ g(-1) = 3/3 = 1

 

Answer: 1

Answer 2

f(x)=x^2+3x+5

g(x)=3x^2

 

f(-2)=(-2)^2+(3)(-2)+5

f(-2)=4-6+5

f(-2)=3

 

g(-1)=(3)(-1)^2

g(-1)=3

 

f(-2)/g(-1)=3/3

f(-2)/g(-1)=1

 

 

Answer 3

Hi Minah,

 

f(-2) =(-2)²  +3(-2) +5 = 4-6+5 = 3

g(-1) = 3 (-1)² = 3

 

f(-2) / g(-1) = 3/3 =1