# How do you simplify #(-7x^4y^2)(-2x^2y^2)#?

##### 1 Answer

Mar 31, 2015

You can divide the calculation in three steps:

- Firts of all, the sign: when multiplying two numbers, look at the sign of the factors. Same sign (which means
#+ * +# or#- * -# ) gives a positive result, while the other cases (i.e.#+ * -# or#- * +# ) gives a negative result. Since you have the multiplication of two negative numbers, the result will be positive. - The numeric part: this is probably the easiest part: you simply need to multiply the two numbers. So, you have
#7*2=14# - Variables: When multiplying two variables, simply add the exponent: so
#x^4*x^2 = x^{4+2} = x^6# , and#y^2 * y^2 = y^{2+2}=y^4# .

After all, writing a power is just a short way for writing a product of several factors, all equal to each other. So, writing the expression in a more complicated fashion, you would have

Now,