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)
Answer:
y = 1/2 (2)x
Step-by-step explanation:
Using the equation y = abx , substitute both of your given points into that equation.
2 = ab2 and 4 = ab3 Solve each equation for a.
2⁄b2 and 4⁄b3 = a Therefore, 2⁄b2 = 4⁄b3
Cross multiply: 2b3 = 4b2 Divide both sides by b2
2b = 4 a = 2/4 = 1/2
b = 2
If y = √(2x + 1), then differentiating both sides implicitly with respect to t gives
dy/dt = 1/2 • 1/√(2x + 1) • 2 • dx/dt = 1/√(2x + 1) • dx/dt
(a) If dx/dt = 9 and x = 4, then
dy/dt = 1/√(2•4 + 1) • 9
dy/dt = 1/√(8 + 1) • 9
dy/dt = 1/√9 • 9
dy/dt = 9/3
dy/dt = 3
(b) If dy/dt = 3 and x = 40, then
3 = 1/√(2•40 + 1) • dx/dt
3 = 1/√(80 + 1) • dx/dt
3 = 1/√81 • dx/dt
3 = 1/9 • dx/dt
dx/dt = 27
Ring ding ding ding ding ding ding ding it’s 4/5
Answer:
The answer to the problem is
y = 134/3
Step-by-step explanation
