One solution to a quadratic equation is 4 - 5i. Find the equation.
1 answer:
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Answer:
No, Matt did not solve the equation correctly
Correct Answer: x = 8
Step-by-step explanation:
4(x + 2) = 30
Step 1: Distribute
4x + 2 = 30 This is his mistake, he should completely distribute 4
to x and 2
Step 2: Subtract 2 from both sides/Isolate x
4x = 28 This part is done correctly, but wrong because of Step 1
Step 3: Divide both sides by 4
x = 7 This is correct, but again, he messed up on Step 1
Step 1: Distribute
Remember to distribute 4 to all terms in the parenthesis.
4(x + 2) = 4(x) + 4(2)
= 4x + 8
4x + 8 = 30
Step 2: Subtract 8 from both sides/Isolate x
Move all the terms that do not belong to x to the other side. We can do this by subtracting 8 from both sides (opposite operation of adding 8)
4x + 8 = 30
4x = 30 - 8
4x = 32
Step 3: Divide both sides by 4/Isolate x
Now we want x by itself. Since x is being multiplied by 4, we have to use the opposite operation, dividing by 4, to have x on one side by itself
4x = 32
4(x) = 32
x = 32 ÷ 4
x = 8
-Chetan K
We want to find the value that makes
To find it we must look at the standard normal table, using the complementary cumulative table we find that
Then, using the z-score we can find the minimum score needed, remember that
Where
σ = standard deviation
μ = mean
And in our example, x = minimum score needed, therefore
Rounding to the nearest integer the minimum score needed is 568, if you get 568 you are at the top 20.1%.