It's best to write the two equations as a vertical column:
8x+14y=4
-6x-7y = -10
Note that if we multiply the 2nd equation by 2, we get -12x - 14y = -20. The reason for wanting this version of the 2nd equation is that its -14y cancels the +14y in the first equation:
-12x - 14y = -20
8x+14y=4
Combine these equations, column by column. We get -4x = -16, which results in x = 4. Now find y by subbing 4 for x in either given equation. If we use the first equation, we get 8(4) + 14y = 4, or 32 + 14y = 4, or 14y = -28. Then y = -2.
The solution to this system of linear equations is thus (4,-2).
Check this result by substitution of these coordinates into -6(4) - 7y = -20:
-24 - 7(-2) = -10. Is this true or not?
-24 + 14 = -10 is true. Thus, (4,-2) is the desired solution.
Answer:
The range is also the whole of R
Step-by-step explanation:
Answer:
Hence first graph is the correct answer.
T I
1 28
2 56
3 84
4 112
Step-by-step explanation:
Given that initial amount P = $400
Simple rate of interest = R = 7% = 0.07
Time t= 1,2,3,4 years.
Then apply Simple interest formula to find the total interest earned in the given years.
I=PRT
for t=1 year
I=PRT=400(0.07)(1)=28
for t=2 year
I=PRT=400(0.07)(2)=56
for t=3 year
I=PRT=400(0.07)(31)=84
for t=4 year
I=PRT=400(0.07)(4)=112
Now we have table as shown below:
T I
1 28
2 56
3 84
4 112
Graphing these points we see that obtained graph best matches with First choice .
Hence first graph is the correct answer.
Step-by-step explanation:
x + 8a = 25 + ax - 7a
x = 5
5 + 8a = 25 + 5a - 7a
5 + 8a = 25 - 2a
5 + 10a = 25
10a = 20
a = 2
