Respuesta :
Answer:
45/4
Step-by-step explanation:
We can interpret the question to have two equation which can be solve simultaneously
a+b=7------------(1)
a-b=2------------(2)
From eqn(2) make a subject of formula
a=2+b--------(3)
Substitute the (3) into eqn(1)
a+b=7------------(1)
2+b+b=7
2b=7-2
2b=5
b=5/2
From equation (3) substitute value of b to find a
a=2+b--------(3)
a= 2+5/2
a=9/2
Then What is the value of a x b ?
9/2× 5/2
=45/4
Answer:
11 1/4
Step-by-step explanation:
a+b=7
a-b=2
adding equations gives us 2a=9 so a= 9/2
b= 7- 9/2= 14-9/2=5/2
therefore a x b= 9/2 x 5/2 =45/4
45/4 in a mixed number is 11 1/4