Answer:
(2x-1)(2x+1)(x^2+2) = 0
Step-by-step explanation:
Here's a trick: Use a temporary substitution for x^2. Let p = x^2. Then 4x^4+7x^2-2=0 becomes 4p^2 + 7p - 2 = 0.
Find p using the quadratic formula: a = 4, b = 7 and c = -2. Then the discriminant is b^2-4ac, or (7)^2-4(4)(-2), or 49+32, or 81.
Then the roots are:
-7 plus or minus √81
p= --------------------------------
8
p = 2/8 = 1/4 and p = -16/8 = -2.
Recalling that p = x^2, we let p = x^2 = 1/4, finding that x = plus or minus 1/2. We cannot do quite the same thing with the factor p= -2 because the roots would be complex.
If x = 1/2 is a root, then 2x - 1 is a factor. If x = -1/2 is a root, then 2x+1 is a factor.
Let's multiply these two factors, (2x-1) and (2x+1), together, obtaining 4x^2 - 1. Let's divide this 4x^2 - 1 into 4x^4+7x^2-2=0. We get x^2+2 as quotient.
Then, 4x^4+7x^2-2=0 in factored form, is (2x-1)(2x+1)(x^2+2) = 0.
Find the number of miles driven by subtracting the odometer readings:
74545 - 74233 = 312 miles driven.
Divide miles driven by gallons of gas used:
312 / 9 = 34.66 = 35 miles per gallon.
Answer:
360 degrees
Step-by-step explanation:
2^x-2=16
+2 +2
——————
2^x=18
(Log)(2))=log (18)
X=log(18)
————-
Log(2)
X=4.169925
Answer:
solution set is (x,y) = (7,6)
Step-by-step explanation:
solving by substitution method
2x +y=20--------------1
6x-5y=12---------------2
from equation 1, solve for y
2x+y=20
y= 20-2x------equation 3
adding value of y in equation 2
6x-5y=12
6x-5(20-2x)=12
6x-100+10x=12
16x= 12+100
16x= 112
x= 112/16
x=7
adding value of x in equation 3
y= 20-2x
y= 20- 2(7)
y=20-14
y=6
so solution set (x,y) = (7,6)
