A chemical company makes two brands of antifreeze. The first brand is 45% pure antifreeze, in the second brand is 70% pure antifreeze. in order to obtain 90 gallons of a mixture that contains 60% of pure antifreeze, how many gallons of each brand of antifreeze must be used?

No matter what I do, I cannot figure out this problem.

Arefrigeration system at your company uses temperature sensors fixed to read celsius (°c) values, but the system operators in your control room understand only the fahrenheit scale. you have been asked to make a fahrenheit (°f) label for the high temperature alarm, which is set to ring whenever the system temperature rises above –10°c. what fahrenheit value should you write on the label?

(50 ) mrs. julien’s and mrs. castillejo’s classes are selling cookie dough for a school fundraiser. customers can buy packages of macadamia nut chip cookie dough and packages of triple chocolate cookie dough. mrs. julien’s class sold 25 packages of macadamia nut chip cookie dough and 30 packages of triple chocolate cookie dough for a total of $221.25. mrs. castillejo’s class sold 5 packages of macadamia nut chip cookie dough and 45 packages of triple chocolate cookie dough for a total of $191.25. (a) write the system of equations that model the problem. be sure to explain which equation represents which situation. (b) find the cost of each type of cookie. show your work. (c) explain which method you used to solve the system and why you chose that method.

The measures of two supplementary angles are (2x + 10)° and (8x + 10)°. what is the measure of the larger angle? a. 16° b. 44° c. 14° d. 138°