Answer:
Mr mehra's salary is 26250
Step-by-step explanation:
suppose,
Mr mehra's salary is x
so,
He spends in food = 30% of x
=(30/100) . x [x%=x/100]
= 30x/100
=3x/10
He spends in charity =10% of x
=10x/100
=x/10
Money left = 15750
so,
x = 3x/10 + x/10 + 15750
⇒x - 3x/10 - x/10 = 15750
⇒(10x-3x-x) /10 = 15750
⇒6x/10 = 15750
⇒6x=157500
⇒x = 157500/6
⇒x = 26250
∴Mr mehra's salary is 26250
Answer:
gradient = 2
Step-by-step explanation:
Calculate the gradient (slope) m using the slope formula
m = 
with (x₁, y₁ ) = (1, 0) and (x₂, y₂ ) = (6, 10) ← 2 points on the line
m =
=
= 2
Let cost of 1 box of red pen = x
Let cost of 1 box of black pen = y
Gaga bought 5 red box and her sister 4 black box then total cost is given by
5x+4y
Given that total cost was $44
so equation will be 5x+4y=44...(i)
After exchange
Gaga= 4 red box + 1 Black box
Sister = 1 red box + 3 Black box
then cost for Gaga = 4x+1y
cost for sister = 1x+3y
Given that cost for both after exchange is same so we get
4x+1y = 1x+3y
or 4x-1x = 3y-1y
or 3x = 2y
or 3x/2=y ...(ii)
plug (ii) into (i)
5x+4y=44
5x+4(3x/2)=44
5x+12x/2=44
5x+6x=44
11x=44
x=4
Now plug value of x into (ii)
y=3x/2=3*4/2=12/2=6
Hence cost of 1 box of red pen = $4
And cost of 1 box of black pen = $6
---
If you want to get solution without solving both equations then just graph both equations and find the intersection point.
You will see that graph intersect at (4,6) which gives x=4, y=6
(-7x² + 3) + (4x² + 2x - 1)
-7x² + 3 + 4x² + 2x - 1
(-7x² + 4x²) + (3 - 1) + 2x collect like terms
-3x² + 2x + 2
hope this helps, God bless!