Solve the system using addion

7x+2y=-13

-7x+y=25

The diagonals of a parallelogram are perpendicular to each other. The perimeter of the parallelogram is 48 feet. Find the lengths of the sides of the parallelogram.

A person's IQ (Intelligence Quotient) is supposed to be a measure of his or her "intelligence." The IQ test scores are normally distributed and are scaled to a mean of 100 and a standard deviation of 15.

Two dice are thrown simultaneously. Given that sum of the numbers is NOT more than 5, what is the probability that sum is more than 3?

How do i put this number into scientific notation? 9,460,730,472,580.8?

Felix borrowed $400 and must pay 12% interest. How much must be paid back in all if he paid it back after 1 year?

The expression 24 (1-x) gives the discounted price of a pair of shorts, where x is the percent of the discount written in decimal form. What does 1-x represent in the expression?

To estimate the height of a tree, a geometry student measures the shadow of the tree that is 30 feet from the base tree. They place a steak at the top of the Shadow. The student is 4 feet from the stake, and the students height is 5.

What is the cube root of 7/6?

Three of the vertices of a rectangle have coordinates (-1, - 1), (6, - 1), and (-1, 2). What are the coordinates of the fourth vertex

The expression 80 and 4,5890 are both equal to one another. True or False