There are 7 red lights and for every 1 red light there are 9 blue lights. how many lights in all?

70

Step-by-step explanation:

We can rewrite the phrase for every '1 red light there are 9 blue lights' as there are 9 blue lights for every red, which may make it slightly clearer.

If there are 7 red lights, and 9 blues for every red, then there are 7*9 blue lights, or 63 blue lights. Now we can add the red and blue lights; 63+7=70, so there are 70 lights in all.

step-by-step explanation:

ok so im not 100% sure but you would start by adding 5.1t and 1.9t beacuse they have the same variable. that is 7t.   then add -3.6 + 1.2 which is -2.4

so then keep that as -2.4 + 7t. i apologize if this is incorrect. best luck on your test < 3