What type of math is this?
25% of what is 30?
and
solve for a: ab=b=3a-d
Your first problem is a percentage problem. 25% = 0.25
0.25 * 30 = 7.5
your doing "is over of equals percnt over 100. so you set it up
30/x =25/100
cross multiply and solve for x
25x= 3000
dicide by 25 for your answer.
this is stuff you learn in algebra. i am confused with the second equation though
But the answer is 120. I have the answers to those questions. I just need to know topics they are included in so I can study.
correction
ab+b=3a-d
Oops, Alex, I misread your problem. I'm sorry.
25% of what is 30
0.25x = 30
x = 30/0.25
x = 120
The first question involves finding a certain percentage of a number, which is a concept in basic arithmetic. To solve the question "25% of what is 30?", you need to find the number that, when multiplied by 25% (or 0.25), gives the result of 30.
To solve this math problem, you can set up an equation. Let's call the unknown number "x". The equation would be: 0.25 * x = 30.
To find the value of x, you can divide both sides of the equation by 0.25:
x = 30 / 0.25
Calculating this, you will get:
x = 120
Therefore, 25% of 120 is 30.
The second question involves solving for a variable "a" in an equation. It seems there might be a misplacement of the equal sign in the equation provided, as you wrote "ab = b = 3a - d". Assuming it was meant to be "ab + b = 3a - d", I'll explain how to solve it.
To solve for "a", you need to isolate the variable on one side of the equation. Here's how you can do it step-by-step:
Step 1: Simplify the equation by combining like terms on both sides.
ab + b = 3a - d
Step 2: Move all terms with "a" to one side of the equation by subtracting 3a from both sides.
ab + b - 3a = -d
Step 3: Rearrange the equation to isolate "a" on one side.
-3a = ab + b - d
Step 4: Divide both sides of the equation by -3 to solve for "a".
a = (ab + b - d) / -3
This gives you the value of "a" in terms of the other variables and constants in the equation.