Answer:
1:5.that is the answer I will send solution later
Answer:
- first rectangle: 18 by 9
- second rectangle 21 by 6
- x = 9
Step-by-step explanation:
The perimeter in each case is double the sum of the side dimensions. Since the perimeters are equal, the sum of side dimensions will be equal:
2x +x = (x +12) +(x -3)
3x = 2x +9 . . . . . . . . collect terms
x = 9 . . . . . . . . . . . . . subtract 2x
Given this value of x, the dimensions of the first rectangle are ...
{2x, x} = {2·9, 9} = {18, 9}
And the dimensions of the second rectangle are ...
{x+12, x-3} = {9+12, 9-3} = {21, 6}
Answer:
The second option
Step-by-step explanation:
For this problem, there are multiple ways to solve. The easiest here is the cross method. For ax²+bx+c, you find 2 numbers that multiply to ac and add to b, which you replace b with.
ac in this case is -8×3, which is -24. b in this case is 23.
You can go through the factor pairs of -24 to find the ones that add to b. These pairs are (1 and -24, -1 and 24, 2 and -12, -2 and 12, 3 and -8, -3 and 8, 4 and -6, -4 and 6). The only pair that adds to 23 is 24 and -1.
You sub this into the original equation, making 3x²+24x-x-8.
From there, you factorise, making 3x(x+8)-x(x+8).
This can be factorised further to (3x-x)(x+8) by collecting like terms.
**This question involves factorising quadratics, which you may wish to revise. I'm always happy to help!
It would be: if you want me to explain let me know
5x+15=90
5x= 75
X=15
Because it’s complementary
