题目7单选题
用公式法解方程3x2+4=12x,下列代入公式正确的是( )A. <img src="https://tihai-oss-cloud.itihey.com/img/b158a0f308d2ef9f2316391082207b25.png">B. <img src="https://tihai-oss-cloud.itihey.com/img/70c11356ee1d9cb0c0db20ff86b661de.png">C. <img src="https://tihai-oss-cloud.itihey.com/img/efe68d782f7dc2c5282088744a66cc29.png">D. <img src="https://tihai-oss-cloud.itihey.com/img/d29eb712f27707bb22ba800f518cf19b.png">