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As shown in the figure, if DF ‖ AC, ∠ C = ∠ D, then DB ‖ EC, please explain the reason
It is proved that: ∵ DF ∥ AC, ∵ d = DBA, and ∵ C = DBA, ∵ DB ∥ EC
A. If B, C and D are four points in order on a straight line, and AC = 10, BD = 8, then the value of AB * CD + BC * ad is equal to____ Please explain the reason
Let AB be x, BC be y, CD be Z. the above is XZ + XY + y ^ 2 + ZY, AC be x + y = 10, BD be y + Z = 8. Multiply to get the previous formula, which is equal to 80
Is y equal to a square times x minus 2 a positive proportion function? If not, please explain the reason!
Y = A & # 178; X-2 is not a positive proportional function
If a ≠ 0, then y = A & # 178; X-2 is a linear function
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