Question 203298
Solve the following:
1. 2x=-3x+9
Add 3x to both sides to get:
5x = 9
Divide both sides by 5 to get:
x = 9/5
======================================
2. 3x/5=-6 


Multiply both sides by 5 to get:
3x = -30
Divide both sides by 3 to get:
x = -10
======================================
3.y/4+2=7 
Subtract 2 from both sides to get:
y/4 = 5
Multiply both sides by 4 to get:
y = 20
======================================

5.16= -2x/3 
Multiply both sides by 3
-2x = 48
Divide both sides by -2 to get:
x = -24
======================================
6. Find f(1) for f(x) =2x^3-3x^2+x-21
f(1) = 2 - 3 + 1 -21
f(1) = -21
======================================
 
7. A function gives the value of C as 2x(22/7)xr . Find C when r=7cm and r=91cm 
C = 2(22/7)r
If r = 7 cm, C = 2*(22/7)*7 = 44
----
If r = 91 cm, C = 2(22/7)*91 = 2*22*13 = 572
=====================================================
Cheers,
Stan H.