Answer:
where should I substitute 8 for x? if its like this 4(8)+y=12 than its y=-20
Step-by-step explanation:
When you see an equation with parenthesis around it, you can use this:
Parenthesis
Exponents
Multiplication
Division
Addition
Subtraction
Otherwise known as PEMDAS.
We can see that in the equation, there are parenthesis, so we can open those. We open parenthesis by taking the number right next to the parenthesis (or outside the parenthesis) and we multiply that number by everything inside. So this is what it would look like:
-2x^2 - 10x + 8
See how the signs changed? This rule only applies when you multiply something, but here is how I think of it:
+ and + always equals +.
- and - always equals +.
- and + always equals -.
+ and - always equals -.
So that's it! Just to be clear, the answer is:
-2x^2 - 10x + 8
Hope I helped, sorry if I'm wrong!
`Mschmindy
Answer:
35
Step-by-step explanation:
15 plus 10 equals 25.
25 plus 10 equals 35.
Hope it helps!
Answer:
Height of fir tree = 9 meters
height of pine tree= 12 meters
Step-by-step explanation:
The combined height of one fir tree and one pine tree is 21 meters. The height of 4 fir trees stacked on top of each other is 24 meters taller than one pine tree.
Let x be the height of fir tree and y be the height of pine tree
Subtract x from both sides
height of 4 fir trees = pine tree +24
Substitute 21-x or y in the above equation
Add x on both sides
Divide by 5 on both sides
x=9
Now plug in 9 for x and find out y
y=12
Height of fir tree = 9 meters
height of pine tree= 12 meters
