4.6 - 3.9= .7cm which is 7mm
Answer:
see explanation
Step-by-step explanation:
Given A is directly proportional to r² then the equation relating them is
A = kr² ← k is the constant of proportion
To find k use the condition when r = 5, A = 75 , then
75 = k × 5² = 25k ( divide both sides by 25 )
3 = k
A = 3r² ← equation of proportion
(a)
when r = 4, then
A = 3 × 4² = 3 × 16 = 48
(b)
when A = 147 , then
147 = 3r² ( divide both sides by 3 )
49 = r² ( take the square root of both sides )
r =
= 7
Answer:
b = 10
-2d = -38
x = -1.2
Step-by-step explanation:
b = 10 and x = -1.2 only have one variable. You can divide -2 to both sides for -2d = -38 getting d = 19.
0.1 = 0.1 have no variable meaning that any number can be correct in the equation
1/3 ≠ 1/3 has a cross in the equal sign meaning that there is no correct answer for the equation.