Hi I hope you are all okay could someone help me with this math question thankyou !!!
y
∝
1
√
x
If
y
=
7
when
x
=
64
find,
x
when
y
=
8
X = pencils, y = pens
8x + 6y = 8.50
4x + 4y = 5.....multiply by -2
----------------
8x + 6y = 8.50
-8x - 8y = -10 (result of multiplying by -2)
-----------------add
-2y = - 1.50
y = -1.50 / -2
y = 0.75 <=== pens cost 0.75
4x + 4y = 5
4x + 4(0.75) = 5
4x + 3 = 5
4x = 5 - 3
4x = 2
x = 2/4
x = 0.50 <== pencils cost 0.50
Y-4X =3 ; 2x-3y=21
Y= 3+ 4x
2x -3( 3+4x)= 21
2x- 9- 12x= 21
-10x -9= 21
-10x -9+9= 21+9
-10x = 30
X= 30/-10= -3
Y= 3+4x = 3+ 4* (-3)= 3-12= -9
The value is the tens place