OK HERE IT IS: There are 4 more girls in Mrs. Pitt's class than Mr. Brown's class. Five girls moved from Mrs. Pitt's class to Mr. Brown's class. Now there are twice as many girls in Mr. Brown's class as there are in Mrs. Pitt's. How many girls were in Mr. Brown's class to begin with? SO MY TEACHER GAVE ME THE ANSWER WHICH IS 7 BUT I NEED TO SHOW THE WORK. PLZZZ HELP ME!!!!!!!!!!!!!!!!! 20 POIINTS FOR BEST ANSWER!!!!!!!!!!!!!!!
Anonymous
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The left side of the equation is Mrs. Pitt's class and the right side is Mr. Brown. x = number of girls
x + 4 = x (4 more girls in Mrs. Pitt's class than Mr. Brown so this equation just sets that equal)
x - 1 = x + 5 ( five girls moved so the +4 turns to -1 and Mr. Brown gets +5)
2x - 2 = x + 5 ( here I multiplied by 2 on Mrs. Pitt's class to make the equation equal because of the " Now there are twice as many..." part)
x - 2 = 5 ( here i begin to solve for x which is Mr. Brown's class original number of girls if you look at the first equation, the right x gets subtracted from the 2x)
x = 7 (theres your answer, just add two on both sides for the final answer)
Hope this helps!
- Austin
Vicente
let B= Mr. Brown's class
so let B+4=C Mrs. Pitt's class
2(C-5)=(B+5) for the new girls in each class and the info about 2X as much girls
2(B+4-5)=(B+5) sub what C=
2(B-1)=(B+5) 2*(B-1)
2B-2=B+5 add the 2
2B=B+7 - the B
so B=7
hope that helps :)