作业帮紧急!12月考 20135月SAT数学If the circumference of a cir le is doubled when its radius r is increased by 4 inches, what is the value of r, in inches?3y=2x-6 y=1-cxIn the equations above,x and y are variables and c is a constant. If no ordered
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紧急!12月考 20135月SAT数学If the circumference of a cir le is doubled when its radius r is increased by 4 inches, what is the value of r, in inches?3y=2x-6 y=1-cxIn the equations above,x and y are variables and c is a constant. If no ordered
紧急!12月考 20135月SAT数学
If the circumference of a cir le is doubled when its radius r is increased by 4 inches, what is the value of r, in inches?
3y=2x-6
y=1-cx
In the equations above,x and y are variables and c is a constant. If no ordered pair of numbers(x,y) satisfies both of the quations above,what is the value of c?
请把过程写出来!谢谢了!
紧急!12月考 20135月SAT数学If the circumference of a cir le is doubled when its radius r is increased by 4 inches, what is the value of r, in inches?3y=2x-6 y=1-cxIn the equations above,x and y are variables and c is a constant. If no ordered
第一题,解 ：2( r+4)π = 2 * 2r π 解得,半径为 r=4
第二题,
3y=2x-6.[1]
y=1-cx.[2]
[1] - [2]*3 得
(2+3c)x-9 =0
2+3c=0 时,方程无解
c = -2/3