Question

Evaluate the following

a) 2x + y ÷ 4 for x = 6 and y = 4

b) 8x² + 5xy - (minus) y³ for x =
3 and y = 2

c) - 3abc- 3 for a = 1 , b = 2 and c = 3

d) 9x² + 3x ÷ 2 + 4 for x = 5


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Answer 1

Answer:

$\bf \: i) \: \: 2x + y \div 4 \\ \bf \: \: 2 \times 6 + 4 \div 4 \\ \bf \: 12 + 4 \div 4 \\ \bf13$

${8x}^{2} + 5xy - {y}^{3} \\( 8 \times {3}^{2} ) +( 5 \times 3 \times 2) - {2}^{3} \\ 72 + 30 - 8 \\ 102 - 8 \\ 94$

$- 3abc - 3 \\ (- 3 \times 1 \times 2 \times 3) - 3 \\ - 18 - 3 \\ - 21$

$9 {x}^{2} + 3x \div 2 + 4 \\ 9( {5}^{2} ) +( 3 \times 5) \div 2 + 4 \\ 9 \times 25 + 15 \div 2 + 4 \\ 225 + 15 \div 2 + 4 \\ 236.5$

hope it helps you dear.