Assuming you means 6.5% tax of a $42 purchase
0.065*42=2.73
tax is $2.73
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)
The value of the constant k when the value of x and y is 7 and 3 respectively in the equation xy=k is 21.
<h3>What is an equation?</h3>
An equation is formed when two equal expressions are equated together with the help of an equal sign '='.
The value of the constant k when the value of x and y is 7 and 3 respectively in the equation xy=k can be written as,

Hence, the value of the constant k when the value of x and y is 7 and 3 respectively in the equation xy=k is 21.
Learn more about Equation:
brainly.com/question/2263981
Y-intercept, where the graph crosses y-axiss is 0. that means in the equation: y = mx + b
b = 0
the m, is slope. looking at the graph you can see the points on the line are connect up 4 right 1. rise/run = slope = 4
y = 4x
Answer:
495
Step-by-step explanation:
First you would do 45/5=9
Then do 9*55=495
YW!!!!