Answer:
X=-4, y=-7
Step-by-step explanation:
6x-5y=11. 1st equation
y=7x+21 2nd equation
6x-5(7x+21)=11. Sub value of y in 2nd equation (7x+22) into 1st equation
6x-35x-105=11. Solve by distributative property
-29x-105=11. Add x values
-29x=116. add 105 to both sides
x=-4. Solve for x
solve for y:
y=7x+21
y=7(-4)+21
y=-28+21
y=-7
check answer by substituting x and y into either equation
6x-5y=11
6(-4)-5(-7)=11
-24+35=11
11=11
0 because the answer is 0.67
Answer:
Step-by-step explanation:
we know that
In this problem
The value of x represent the radius of the circle
so
Applying the Pythagoras theorem in the right triangle of the figure, you can find the radius of the circle O
see the attached figure to better understand the problem
square root both sides
9514 1404 393
Answer:
3a by 4a
Step-by-step explanation:
For dimensions L and W, the area and perimeter are ...
A = LW = 12a^2
P = 2(L+W) = 14a
Using the second equation, we can find L:
L +W = 7a . . . . . divide by 2
L = 7a -W
Substituting into the area formula gives the quadratic ...
(7a -W)(W) = 12a^2
W^2 -7aW +12a^2 = 0 . . . . arrange in standard form
(W -3a)(W -4a) = 0 . . . . . . . factor (find factors of 12 that total 7)
Then we have the two solutions ...
W = 3a, L = 4a
W = 4a, L = 3a
The rectangle dimensions are 3a by 4a.
