Answer:
Randall: 44, Amy: 35
Step-by-step explanation:
Four years ago, their age added up to 71. Since four years have passed and they've each grown four years older since then, their ages added up together is 79. Here is the equation for Amy: x + (x + 9) = 79. We can simplify to get 35. Now we add 9 to 35 to get Randall's age. So, Amy's age is 35 and Randall's age is 44, and 35 + 44 = 79.
Hey there!
First, multiply the second equation by -2 as the problem states. When you multiply the second equation by -2, you get:
-2x+4y=2
Now, add this equation to the first equation in which you simply combine like terms:
2x+y=3
+
-2x+4y=2
=
5y= 5
In conclusion, the correct answer would be the first choice.
Answer:
Step-by-step explanation:
First, we need to write down the equations so we can have a vision of the equations.
3x - 6y = -12
x - 2y = -8
Now we find the simpler equation, and we make it to where one of the variables is on one side.
Let's use the bottom equation.
x = 2y - 8
Now we plug in the equation to the other equation.
3(2y - 8) - 6y = -12
6y - 24 - 6y = -12
-24 = -12
0 = 12
This is a false statement. 0 does not equal 12. That means that the equation has no solutions.
400 divided by 42 = 9.523809
<u>5x² + 9x - 1</u><u> is the expression that represents a </u><u>quadratic expression</u><u>.</u>
What is quadratic expression?
- Quadratic expression is an expression with the variable with the highest power of 2.
- The word quadratic is derived from the word quad which means square.
- The expression should have the power of two and not higher or lower.
A quadratic expression is of the form
ax² + bx +c = 0 where a ≠ 0
The give options are-
9x - 2
5x² + 9x - 1
-2x³ + 8x² - 7x +1

From the given options, the only expression which is quadratic is
5x² + 9x - 1
wChoose the expression that represents a quadratic expression. 9x − 2 5x2 9x − 1 −2x3 8x2 − 7x 1 x4 − 12x3 8x2 −here a =5, b=9 and c=-1
Therefore, 5x² + 9x - 1 is the expression that represents a quadratic expression.
Learn more about quadratic expression.
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