I need help explaining

Sure.

Step-by-step explanation:

So X is a variable meaning its a letter that represents a number. When there are a number and a variable (or a letter) like this 2x or 9y it means you are going to multiply the number by the variable. In this case it is 7 times x is equal to 21 so all we have to do is find what times 7 is equal to 21 and that number is 3. So if 7*x=21 is 7*3=21 then x=3. If you have any questions ill be more than open to answering them, hopefully this helped. Have a good day/night.

answer: 1 and 3

step-by-step explanation:

dilation scale factor 2: starting with δabc, draw the dilation image of the triangle with a center at the origin and a scale factor of two. notice that every coordinate of the original triangle has been multiplied by the scale factor (x2). dilation with scale factor 2, multiply by 2.