OK to solve this, we have to solve each system presented through elimination or substitution and find which one is equivalent to that of the teacher's!
First let's solve for the teacher's:
-2x+5y=10
-3x+9y=6
Solve by substitution (I think elimination might be easier to do for this one, but I don't really remember 100% sorry!)
Isolate the x (or y) variable in the first equation
-2x+5y=10
-2x=10-5y
Substitute x into the next equation and solve for y
-3(10-5y/2)+9y=6
3*10-5y/2+9y=6
(multiply both sides by 2)
3(10-5y)+18y=12
30-15y+18y=12
30+3y=12
3y=-18
y=-6
Substitute in x
x= -10-5(-6)/2
x=-20
TEACHER'S ANSWER (-20,-6)
GOKU
x-3y=-2
-2x+5y=-7
Do the same as above
Solve for x
x-3y=-2
x=3y-2
Plug in
-2(3y-2)+5y=-7
4-6y+5y=-7
4-y=-7
-y=-11
y=11
x=(3(11)-2)
x=31
GOKU'S ANSWER (31, 11)
SELINA:
-5x+14y=16
-3x+9y=12
One last time!! :)
-5x+14y=16
-5x=16-14y
x=(16-14y)/-5
-3(-(16-14y/5)+9y=12
3*16-14y/5+9y=12
3*16-14y+45y=60
48-42y+45y=60
48+3y=60
3y=12
y=4
x=-(16-14(4))/5
x=8
SELINA'S ANSWER
(8,4)
So neither Goku or Selina got the same answer as the teacher
Answer:
1.5
Step-by-step explanation: please brainliest!
Answer:
Perimeter = 10x + 8 units.
Area = 6x^2 + 13x - 5 units^2.
Step-by-step explanation:
The perimeter is 2*length + 2*breadth
= 2(2x + 5) + 2(3x - 1)
= 4x + 10 + 6x - 2
= 10x + 8 units.
The area = length * breadth
= (2x + 5)(3x - 1)
= 6x^2 - 2x + 15x - 5
= 6x^2 + 13x - 5 units^2.
The interest paid is Rs 10000
The rate of interest is 20%
Step-by-step explanation:
Step 1 :
Amount borrowed by Mr. Satyal = Rs 50000
Amount repaid = Rs 60000
Interest is charged on the principal amount and the amount repaid will be the sum of the interest paid plus the principal amount
Hence the interest paid is 60000 - 50000 = Rs 10000
Step 2:
The rate of interest is calculated as follows :
Divide the interest calculated by the principal amount and is expressed as percentage.
Hence the interest rate = × 100 = 20%
Step 3 :
The interest paid is Rs 10000
The interest rate is 20%