Here is one way to solve for x.
Step 1) 2x^2-7=9
Step 2) 2x^2-7+7=9+7
Step 3) 2x^2=16
Step 4) (2x^2)/2=16/2
Step 5) x^2=8
Step 6) sqrt(x^2)=sqrt(8)
Step 7) |x|=sqrt(8)
Step 8) x=sqrt(8) or x=-sqrt(8)
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Below are explanations/reasons to each of the steps above.
Step 1) Original equation
Step 2) Add 7 to both sides
Step 3) Combine like terms
Step 4) Divide both sides by 2
Step 5) Simplify
Step 6) Apply the square root to both sides. The notation "sqrt" is shorthand for "square root"
Step 7) Use the rule that sqrt(x^2) = |x| for all real numbers x
Step 8) Use the rule that if |x| = k then x = k or x = -k for some fixed number k.
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The two solutions are
x = sqrt(8) or x = -sqrt(8)
Option B. 55° is the correct answer
Step-by-step explanation:
"The sum of interior angles of a triangle is always 180°"
Given
m∠A=(3x+1)°
m∠B=(2x-1)°
m∠C = 40°
We know that
m∠A+m∠B+m∠C=180°
Putting the values of angles

Subtracting 40 from both sides

Dividing both sides by 5

We have to find Angle B,
So
m∠B = 2x-1 = 2(28)-1 = 56-1 = 55°
Hence,
m∠B=55°
Option B. 55° is the correct answer
Keywords: Triangle, Interior angles
Learn more about triangles at:
#learnwithBrainly
Z- score is a statistical tool that is used to determine the probability of finding a number or a value under a normal distribution plot. A normal distribution assumes that the mean is equal to zero and that the standard deviation is equal to 1. Using the z-score table, we can find the probability either on the right side or the left side. Using the table hence, we find the probability to the left of the value. The probability that is equivalent to the unknown z should be equal to 0.5 + (0.27/2) = 0.635. 0.5 comes from the assumption that the area under the curve on each side is 50% of the total. The equivalent z score is equal to z = 0.345.
(3^6 / 3^5)^2 = (3^(6 - 5))^2 = (3^1)^2 = 3^2 = 9