Answer:
12r^2 +r -7
Step-by-step explanation:
9r^2 +4r -7 +3r^2 -3r
Combine like terms
9r^2 +3r^2 +4r -3r -7
12r^2 +r -7
Because of the relatively large coefficients {9, 42, 49}, applying the quadratic formula would be a bit messy. Instead, I've chosen to "complete the square:"
9x^2 + 42x + 49 = 0 can be re-written as 9 [ x^2 + (42/9)x ] = -49
Dividing both sides by 9, we get [ x^2 + (42/9)x ] = - 49/9
Completing the square: [ x^2 + (42/9)x + (21/9)^2 - (21/9)^2 ] = -49/9
[ x + 21/9 ]^2 = 441/81 - 441/81 = 0
Then [ x + 21/9 ] = 0, and x = -21/9 (this is a double root).
Answer:
40
Step-by-step explanation:
That is rounded
The answer is the third option, which is:
<span> y = x^2 + 5x + 3
6x + y = −27
The explanation is shown below:
1. When you solve this problem you have the following solution:
x=-6
y=9
x=-5
y=3
2. As you can see the solution corresponds with the graph shown above.
3. You can give value to the variable x of the first equation and values to the x of the second equation, and plot each point obtain. You will see that the parabola and the line, touch each other at the points (-5,3) and (-6,9)</span>
