Answer:
Step-by-step explanation:
x²+10x+21=0
x²+10x+(10/2)²-(10/2)²+21=0
x²+10x+25-25+21=0
(x+5)²-4=0
(x+5)²=4
(x+y)²=(x+y)(x+y)=x(x+y)+y(x+y)=x²+xy+xy+y²=x²+2xy+y²
(x+y)²=x²+2xy+y²
coefficient of x=2y
y²=[(coefficient of x)/2]²=(2y/2)²=y²
Answer:
huh? and it wont load the picture
Step-by-step explanation:
Answer:

Step-by-step explanation:
z=5x-11y
+11y on both sides
z+11y=x
divide by 5 on both sides
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Answer:
9
Step-by-step explanation:
9.45 is rounded down to 9 because the number must reach half to round up. To round up to 10, it must be 9.5. hope this helps