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JAMB Mathematics Past Questions & Answers - Page 178

886.

The solution to the simultaneous equations 3x + 5y = 4, 4x + 3y = 5 is

( $\frac{-13}{11}, \frac{1}{11}$ )

( $\frac{13}{11}, \frac{1}{11}$ )

( $\frac{13}{11}, \frac{-1}{11}$ )

( $\frac{11}{13}, \frac{1}{11}$ )

(13, 11)

View answer & explanation

Correct answer is B

3x + 5y = 4, 4x + 3y = 5

3x + 5y = 4 x 4

4x + 3y = 5 x 3

12x + 20y = 16.....(i)

12x + 9y = 15.......(ii)

subtract eqn.(ii) from eqn.(i)

11y = 1

y = $\frac{1}{11}$

12x + 20 x $\frac{1}{11}$ = 16

12x = $\frac{156}{11}$

x = $\frac{13}{11}$

= $\frac{13}{11}, \frac{1}{11}$

887.

A housewife bought 3 kilograms of garri at N13.00 per kg. She deposited N160. 00 for half a cow and bought 24 oranges at 10k each. She came back home with N20.60. She therefore left home with

N220.00

N222.00

N201.40

N202.00

N180.80

View answer & explanation

Correct answer is B

3 kg of garri at N13.00 per kg = N39.00
half a cow = N160.00
24 oranges at 10k each = N2.40
balance = N20.60
Adding all together = N222.00

888.

The solution to the quadratic equation 5 + 3x - 2x² = 0 is

( $\frac{5}{2}$ , 1)

(5, 3)

-( $\frac{5}{2}$ , -1)

( $\frac{5}{2}$ , -1)

View answer & explanation

Correct answer is D

5 + 3x - 2x² = 0, (x + 1)(5 - 2x) (expand to check)

(x + 1)(5 - 2x) = 0

when x = 1 = 0, x = -1

when 5 - 2x = 0, x = $\frac{5}{2}$ - 1

889.

Simplify $\frac{3}{2x - 1}$ + $\frac{2 - x}{x - 2}$

$\frac{2 - x}{(2x - 1)(x - 2)}$

$\frac{5 - x}{(2x - 1)(x - 2)}$

$\frac{4 - 2x}{2x - 1}$

$\frac{6 - 3x}{(2x - 1)(x - 2)}$

View answer & explanation

Correct answer is C

$\frac{3}{2x - 1}$ + $\frac{2 - x}{x - 2}$

= $\frac{3}{2x - 1}$ - $\frac{x - 2}{x - 2}$

= $\frac{3}{2x - 1}$ - 1

= $\frac{3 - (2x - 1)}{2x - 1}$

= $\frac{3 - 2x + 1}{2x - 1}$

= $\frac{4 - 2x}{2x - 1}$