Somebody please give me the answer (AND DO NOT GIVE ME A DOWNLOAD LINK. I AM NOT RISKING MY COMPUTER FOR JUST A MATH QUESTION.). Give me the shortest answer and a step-by-step explanation.

Which of the following system of equation is not equal to the system of equations is not equal to the system of equations shown below

Some boys and girls were asked if they had a pet. one third of the group were boys. there were 20 boys. 20% of the girls had a pet. boys with a pet : girls with a pet = 1 : 5 i need to know how many girls there are.

The area (a) of a circle with a radius of r is given by the formula and its diameter (d) is given by d=2r. arrange the equations in the correct sequence to rewrite the formula for diameter in terms of the area of the circle.