Answer:
The base is 4cm and the height is 5cm.
Step-by-step explanation:
This is a solve the system question. Call H the height of the triangle and B the base. The question tells us:

and

Sub the first equation into the second (as H is already isolated). You will end up with a quadratic equation - solve that any way you wish (e.g. quadratic formula). I've provided the factored form below which shows you the roots:

In this question, we take B=4. You can't have a negative side length so the other answer is eliminated. Now sub the value for B into either of the original equations. I'll use the first, again because H is already isolated:

Answer:
The required expression is 
Step-by-step explanation:
Consider the provided information.
A tissue can be 0.000075 meters thick and we need to represent it into scientific notation.
Steps to write a number in scientific notation.
- Move the decimal place to the right so that the new number from 1 up to 10.
- Determine the exponent, the exponent is the number of times you moved the decimal.
Now, consider the number 0.000075
Move the decimal point to 5 place right so that the new number from 1 up to 10.
Now, put the exponent the number of times you moved decimal. 
Hence, the required expression is 
Answer: The answer is 4. 7+(-3) is like 7 minus 3.
Step-by-step explanation: