Answer:
13
Step-by-step explanation:
Set Susan's present age as x, her age from 3 years ago as x-3, and her age in three years as 2(x-3)
Since her age in seven years = 2 times as old as she way 3 years ago, set up the equation:
x+7 = 2(x-3)
x+7 = 2x-6
x = 13
Answer:
Yes. Her solution is correct.
Step-by-step explanation:
Let's check if Jenna solution is correct:
To solve the equation 2x^2 +5x - 42 = 0, we can use Bhaskara's formula:
D = b^2 - 4ac = 25 + 4*2*42 = 25+336 = 361
sqrt(D) = 19
x1 = (-5 + 19)/4 = 14/4 = 7/2
x2 = (-5 - 19)/4 = -24/4 = -6
We must agree with Jenna's solution, because the values she found as solution are correct: with we replace these values of x in the equation, we will find 0 = 0, which is correct and proves that these values are the solution of the equation.
Answer:
83
Step-by-step explanation:
The 126 angle is an exterior angle of the triangle.
The 43 and x angles are the two remote interior angles of the 126 angle.
<em>Theorem:</em>
<em>The measure of an exterior angle of a triangle equals the sum of the measures of the remote interior angles.</em>
x + 43 = 126
x = 83
