Mr. porter owns a house. when he first bought the house it was valued at d dollars. since then, the value of the house has increased. mr. porter writes the equation below to express the current value of his house. d+0.21d=1.21d d+0.21d=1.21d mr. porter claims that the value of his house has increased by 121% 121%, since 1.21 is equal to 121% 121%. decide if mr. porter is correct. if he is correct, enter 121 below. if he is not correct, enter the correct percent increase.

Mr. Porter's claim was not correct and it will be a 21% increment.  

Step-by-step explanation:

The value of the house when Mr. Porter bought the house was d.

The present value of the house is given by d + 0.21d = 1.21d.

Hence, the increase in the value of the house is 0.21 d and the final value of the house is 1.21d.

So, if Mr. Porter claims that the value of his house has increased by 121%, then his claim is wrong. The increase in value is only by 0.21d i.e. by 21% and after this increment, the value becomes 1.21d i.e. 121%.

Therefore, his claim is not correct and it will be a 21% increment. (Answer)

answer: do you still need this?

i would have to say it is c.