Question

s=-4.9t²+245t+14.7
s=-4.9(t²-245/4.9t)+14.7
s=-4.9(t²-50t)+14.7
s=-4.9(t²-50+625-625)+14.7
s=-4.9(t²-50+625)+(-4.9)(-625)+14.7
s=-4.9(t-25)²+30625.5+14.17
s=-4.9(t-25)²+3077.2


as you can see on the process of the problem on the part that says...s=-4.9(t²-50+625-625)+14.7...the +625-625 on the next step are on different positions like...-4.9(t²-50+625)...and(-4.9)(-625)...i want to know why and why the negative 625 its multiplying by the negative 4.9 please if somebody can explain me all this problem

Answer 1

the line

.....s=-4.9(t²-50+625-625)+14.7 ......
has a typo, should have been

s=-4.9(t²-50t+625-625)+14.7 , look at the bold part in the next line
s=-4.9(<b>t²-50t+625</b>-625)+14.7
s=-4.9[(t-25)²-625)]+14.7 , now the -4.9 has to be multiplied by both terms inside the square bracket
s = -4.9(t-25)² - 4.9(-625) + 14.7
s = -4.9(t-25)² + 3077.2