Answer:
Step-by-step explanation:
1) Eliminate parentheses:
0.1x +18.8 = -4 +2x
22.8 = 1.9x . . . . . . . . . add 4 - 0.1x
12 = x . . . . . . . . . . . . . divide by 1.9
__
2) Eliminate parentheses:
-16 +4x = 0.8x +12.8
3.2x = 28.8 . . . . . . . . add 16 - 0.8x
x = 9 . . . . . . . . . . . . . .divide by 3.2
_____
<em>Comments on the solutions</em>
The expression we add in each case eliminates the constant on one side of the equation and the variable term on the other side. That leaves an equation of the form ...
variable term = constant
We choose to eliminate the smaller variable term (the one with the coefficient farthest to the left on the number line). Then the constant we eliminate is the on on the other side of the equation. This choice ensures that the remaining variable term has a positive coefficient, tending to reduce errors.
__
You can work these problems by methods that eliminate fractions. Here, the fractions are decimal values, so are not that difficult to deal with. In any event, it is good to be able to work with numbers in any form: fractions, decimals, integers. It can save some steps.
The height of an oak tree (which depends on the age of the tree) is 100
Answer:
4
Step-by-step explanation:
25% is the same as 1/4.
1 is 1/4 of what number?
Answer: 4
You can also answer it with an equation.
Let x = the number you are looking for.
1 is 25% of x can be written as the following equation.
25% of x = 1
0.25x = 1
Multiply both sides by 4.
x = 4
Answer: 4
Answer:
<h2>132.25π m²</h2>
Step-by-step explanation:
The circumference of a circle is 23π
On the other hand, The circumference of a circle = 2×π×r ; where r is the radius.
then
by equating the last two expressions we get: 23π = 2πr then r = 23/2
then
the area = π × r² = (23/2)²×π = (132.25)×π
