Answer:
He failed to check for extraneous solutions
Step-by-step explanation:
sqrt(x+6) -4 =x
Add 4 to each side
sqrt(x+6) -4+4 =x+4
sqrt(x+6) =x+4
Sqaure each side
(sqrt(x+6))^2 =(x+4)^2
x+6 = x^2 +8x+16
Subtract 6 from each side
x = x^2 +8x +10
Subtract x from each side
0 = x^2 +7x +10
Factor
0 = (x+5) (x+2)
Using the zero product property
x=-5 x=-2
Check the solutions
sqrt(-5+6) -4 =-5
sqrt(1) -4 = -5
1-4 =-5
-3 does not equal -5 not a solution
sqrt(-2+6) -4 =-2
sqrt(4) -4 = -2
2-4 =-2 is a solution
Step-by-step explanation:
tan(2x) = sin(2x)/cos(2x) = 2sinxcosx/(cos^2x - sin^2x).
Dividing the num- and denominator by sinxcosx, we get
2/(cosx/sinx - sinx/cosx) = 2/(cotx - tanx)
cotA + cotB = cosA/sinA + cosB/sinB
We just add them like fractions, with a common denominator of sinAsinB
(cosAsinB + sinAcosB)/sinAsinB
Note that sinAcosB + sinBcosA = sin(A+B)
Therefore we have
sin(A+B)/sinAsinB
Answer: 33% is moisture content
Step-by-step explanation:
120kg - 80kg = 40kg
40 of 120 is %
Work:
40/120 = 0.33
0.33x100
= 33%
Answer: 2
explanation: so they have 6 teaspoons of salt but they need to know how many are in table spoons. the ratio is 3:1 so 3 teaspoons is equal to 1 table spoon so if you do 3:1 times 2 you get 6:2 or 6 teaspoons of salt is equal to 2 tablespoons of salt
So take out the paretnthaseees
4x+5+15x-3
4x+15x+5-3
19x+2