D since (-5 x -5) = 25 and (7 x -8) = -56. Add 25 and -56 and your answer is D. -31
For this case we must follow the steps below:
step 1:
We place each of the given points on a coordinate axis
Step 2:
We join the AC points (represented by the orange line)
We join the BD points (represented by the blue line)
It is observed that the resulting figure after placing the 4 points on a coordinate axis, turns out to be a rhombus.
In addition, the blue and orange lines turn out to be perpendicular, that is, they have an angle of 90 degrees between them. This can be verified by finding the slopes of each of the two straight lines (blue and orange), which must be opposite reciprocal, that is, they comply: 
In this case, the slope of the orange line is
and that of the blue line is 
Then
, it is verified that they are perpendicular.
Thus, the conclusion is that ABCD is a rhombus and AC is perpendicular to BD.
Answer:
See attached image
Option D
Answer:
Gabby received
7 nickels
10 dimes
3 quarters
Step-by-step explanation:
Let
x----> the number of dimes
y----> the number of nickels
z---> the number of quarters
Remember that
1 dime=$0.10
1 nickel=$0.05
1 quarter=$0.25
we know that
0.10x+0.05y+0.25z=2.10 ------> equation A
x=y+3-----> equation B
z=y-4 -----> equation C
substitute equation B and equation C in equation A and solve for y
0.10(y+3)+0.05y+0.25(y-4)=2.10
0.10y+0.30+0.05y+0.25y-1=2.10
0.40y=2.10-0.30+1
0.40y=2.80
y=7 nickels
<em>Find the value of x</em>
x=y+3 -----> x=7+3=10 dimes
<em>Find the value of z</em>
z=y-4 -----> z=7-4=3 quarters
therefore
Gabby received
7 nickels
10 dimes
3 quarters
Answer:
x = - 56/9 or -6.2
Step-by-step explanation:
Answer:
no
Step-by-step explanation: