A metal alloy weighing 5kg and containing 22% iron melted and mixed with 12 kg of a different alloy which contains 90% iron. What percent of the resulting alloy is iron?

70%

Step-by-step explanation:

Given the weight of the first alloy as 5kg(22% iron) and the second as 12kg(90% iron:

#First, we find the weight in kgs of the iron in both alloys:

Hence, the weight of iron in the resulting alloy is 11.9kg.

#From the given info,the total mass of the alloy is 5+12=17kg

Therefore, the % of iron is calculated as :

Hence, 70% of the resulting alloy is iron.

infinitely many solutions

step-by-step explanation:

we have been given the equation;

2(2x + 3) = -4 + 2(2x + 5)

we need to determine the value of x.

2(2x + 3), we expand this expression to obtain 4x + 6

similarly 2(2x + 5) will become 4x + 10

now we have;

4x + 6 = -4 + 4x + 10

4x + 6 = 4x + 10 - 4

4x + 6 = 4x + 6

the expression on the left hand side is identical to the one on the right hand side. therefore, we are looking at just a single straight line whose equation is;

y = 4x + 6

consequently, we shall have infinitely many solutions

d

step-by-step explanation: