Expression 2a + b represents the situation (total cost) of buying a apples and b bananas.
Solution:
Given that Daryl is buying apples and bananas.
He bought (a) pounds of apples that cost \$2 per pound.
He bought (b) pounds of bananas that cost \$1 per pound.
Need to write an expression which represents the situation.
Cost of 1 pound of apple = 2
\text { So cost of } a \text { pounds of apple }=a \mathrm{x} \text { Cost of } 1 \text { pound of apple }=a \mathrm{x} 2=2 a
Cost of 1 pound of banana =1
\text { So cost of } b \text { pounds of banana }=b \text { x Cost of } 1 \text { pound of banana }=b \times 1=b
Total cost of apples and banana = 2a + b
Hence, the required expression is 2a + b.