Answer:
-4.54 and 1.54
Step-by-step explanation:
This is a quadratic equation
Let Δ be our discriminant :
- a= 1
- b= 3
- c= -7
- Δ = 3²-4*1*(-7)= 37≥0
so we have two solutions : x and y
x =( -3-
)/2 = -4.54
y= ( -3+)/2= 1.541
then the solutions are -4.54 and 1.54
First, I would write the problem vertically because it just helps me better.
7x+2y=10
-7x+1y=-16
Then, I would add downwards.
7x+2y=10
+ -7x+1y=-16
-------------------
0x+3y=-6
Now, divide 3 from both sides.
3y=-6
--- ---
3 3
y=-2
Now, plug in -2 for y in any equation to get x.
7x+2(-2)=10
Combine like terms
7x-4=10
Add 4 to both sides
7x-4=10
+4 +4
-------------
7x=14
Divide each side by 7.
7x=14
---- ---
7 7
x=2
So your solution is
(2,-2)
To check the solution, plug in the x and y values in both equations.
7(2)+2(-2)=10
14-4=10
10=10
-7(2)-2=(-16)
-14-2=-16
-16=-16
Therefore, the solution works.
<u>You must always plug in the x and y values into both equations to check the solution because sometimes the solution will work for one and not the other.</u>
The solution must work to both equations in other for it to be right.
Answer:
9
Step-by-step explanation:
because 4+ 5 is= 9
Answer is 3 hope this helps
