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Multiplying (ii.) by -9, and subtracting the result from (i.),

we get

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104x+156-80x +240 +5x2 = 16x2+24x,

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x = 3.

(2) (x+2) (c −3) + 2(2+cx) = 0,

cx+2c-3x-6+4+2cx=0,

3Cx-3x=2— 26,
3x(c− 1) = 2(1−c),

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39

x

39

x + 1/1/

= time taken to walk 39 miles at ordinary rate,

=

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6. Let x= number of party,

120

then = number of shillings each had to pay,

120

x

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Then +2=what each had to pay =

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=

240+5

2x

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x2 + 100x= = 11900,

x2 + 100x+(50)2 = 11900 + 2500 = 14400.

x+50=120.
x= £70.

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(1) 2x-y=80.

(2) 47x-18y = 2100.

Then from (1), 36x-18y=1440, (2), 47x-18y=2100.

Subtracting (1) from (2),

11x=660,

x=60.

From (1), 120-y=80,

y = 40.

PROBLEMS LEADING TO SIMPLE EQUATIONS OF THE FIRST DEGREE OF TWO OR MORE UNKNOWN QUANTITIES.

1. Let x = numerator, y = denominator of required fraction.

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3. Let y=price per score in pence of small. Then y + 1 = price per score in pence of large. Also let x = number bought of each kind.

Then price paid for small=x.y

20

19 99 large = *(y+1)

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