20分 數學難題x2 26-4-2010交

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1. If both (0,1) and (-1/2,0) lie on the graph of the equation y=ax+b, fine the
values of a and b.

y=ax+b
1=a0+b (put point (0,1) into equation
b=1

y=ax+b
0=-0.5a+1 (Put point (-1/2,0) and b=1 into equation)
0.5a=1
a=2


2. If both (-1/2,0) and (0,2) lie on the graph of the equation y=ax+b, fine the
values of a and b.

Same as question 1:
y=ax+b
2=a.0+b (put point (0,2) into equation)
b=2

y=ax+b
0=-0.5a+2 (put point (-0.5,0) and b=2 into equation)
0.5a=2
a=4